Method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

ABSTRACT

A method of manufacturing a semiconductor device is disclosed. The method includes forming a film on a substrate by performing a cycle a predetermined number of times, wherein the cycle includes non-simultaneously performing: supplying a precursor gas to the substrate in a process chamber; exhausting the precursor gas in the process chamber through an exhaust system; confining a reaction gas, which differs in chemical structure from the precursor gas, in the process chamber by supplying the reaction gas to the substrate in the process chamber while the exhaust system is closed; and exhausting the reaction gas in the process chamber through the exhaust system while the exhaust system is opened.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is a continuation of U.S. patent applicationSer. No. 14/619,318 filed on Feb. 11, 2015 and claims priority under 35U.S.C. §119 of Japanese Patent Application No. 2014-024480, filed onFeb. 12, 2014, the entire contents of which are hereby incorporated byreference.

TECHNICAL FIELD

The present disclosure relates to a method of manufacturing asemiconductor device, which includes a procedure for forming a thin filmon a substrate, a substrate processing apparatus, and a recordingmedium.

BACKGROUND

As an example of procedures of manufacturing a semiconductor device suchas a flash memory, a DRAM, and the like, a procedure of forming a filmon a substrate is often carried out, where a cycle thatnon-simultaneously performs a process of supplying a precursor gas to asubstrate and a process of activating a reaction gas, which differs inchemical structure from the precursor gas, and supplying the activatedreaction gas to the substrate is performed a predetermined number oftimes.

However, depending on a process temperature during the film formingprocess, the activation of the reaction gas may be insufficient, whichmay deteriorate productivity of forming a film and lower the quality ofthe film. A method of activating a reaction gas with plasma may beemployed, but the high energy of plasma in this method may damage asubstrate.

SUMMARY

The present disclosure provides some embodiments of a technology capableof improving productivity of a film forming process and quality of afilm without having to use plasma when such a film is formed on asubstrate using a precursor gas and a reaction gas.

According to one embodiment of the present disclosure, there is provideda technique, including forming a film on a substrate by performing acycle a predetermined number of times, the cycle includingnon-simultaneously performing: supplying a precursor gas to thesubstrate in a process chamber; exhausting the precursor gas in theprocess chamber through an exhaust system; confining a reaction gas,which differs in chemical structure from the precursor gas, in theprocess chamber by supplying the reaction gas to the substrate in theprocess chamber while the exhaust system is closed; and exhausting thereaction gas in the process chamber through the exhaust system while theexhaust system is opened

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a configuration of a verticalprocessing furnace in a substrate processing apparatus that isappropriately employed in one embodiment of the present disclosure, inwhich a portion of the processing furnace is shown in a vertical crosssection.

FIG. 2 schematically illustrates a configuration of the verticalprocessing furnace in the substrate processing apparatus that isappropriately employed in one embodiment of the present disclosure, inwhich a portion of the processing furnace is shown in a cross sectiontaken along the line A-A in FIG. 1.

FIG. 3 schematically illustrates a configuration view of a controller ofthe substrate processing apparatus that is appropriately employed in oneembodiment of the present disclosure, in which a control system of thecontroller is shown in a block diagram.

FIG. 4 illustrates gas supply timings and change of an internal pressureof a process chamber in a film forming sequence according to oneembodiment of the present disclosure.

FIG. 5 illustrates Modification 1 of gas supply timings in a filmforming sequence according to one embodiment of the present disclosure.

FIG. 6 illustrates Modification 2 of gas supply timings in a filmforming sequence according to one embodiment of the present disclosure.

FIG. 7 illustrates Modification 4 of gas supply timings in a filmforming sequence according to one embodiment of the present disclosure.

FIG. 8 illustrates Modification 14 of gas supply timings in a filmforming sequence according to one embodiment of the present disclosure.

FIG. 9 illustrates Modification 20 of gas supply timings in a filmforming sequence according to one embodiment of the present disclosure.

FIG. 10A illustrates change of an internal pressure of a process chamberin a film forming sequences of Example 1.

FIG. 10B illustrates change of an internal pressure of a process chamberin a film forming sequences of Example 2.

FIG. 10C illustrates change of an internal pressure of a process chamberin a film forming sequences of Example 3.

FIG. 11 illustrates change of an internal pressure of a process chamberin a film forming sequence of a comparative example.

FIG. 12 illustrates film forming rates of an SiCN film in the examplesand the comparative example.

FIG. 13A illustrates a chemical structural formula of BTCSM.

FIG. 13B illustrates a chemical structural formula of BTCSE.

FIG. 13C illustrates a chemical structural formula of TCDMDS.

FIG. 13D illustrates a chemical structural formula of DCTMDS.

FIG. 13E illustrates a chemical structural formula of MCPMDS.

FIG. 14A illustrates a chemical structural formula of borazine.

FIG. 14B illustrates a chemical structural formula of a borazinecompound.

FIG. 14C illustrates a chemical structural formula ofn,n′,n″-trimethylborazine.

FIG. 14D illustrates a chemical structural formula ofn,n′,n″-tri-n-propylborazine.

FIG. 15 schematically illustrates a configuration of a verticalprocessing furnace in a substrate processing apparatus that isappropriately employed in another embodiment of the present disclosure,in which a portion of the processing furnace is shown in a verticalcross section.

FIG. 16A schematically illustrates a configuration of the verticalprocessing furnace in the substrate processing apparatus that isappropriately employed in the embodiment of the present disclosure, inwhich a portion of the processing furnace is shown in a vertical crosssection.

FIG. 16B schematically illustrates another configuration of the verticalprocessing furnace in the substrate processing apparatus that isappropriately employed in the embodiment of the present disclosure, inwhich a portion of the processing furnace is shown in a vertical crosssection.

DETAILED DESCRIPTION

<One Embodiment of the Present Disclosure>

One embodiment of the present disclosure is described below withreference to FIGS. 1 to 3.

(1) Configuration of Substrate Processing Apparatus

As illustrated in FIG. 1, a processing furnace 202 includes a heater 207serving as a heating unit (i.e., a heating mechanism). The heater 207has a cylindrical shape and is supported by a heater base (not shown)serving as a support plate so as to be vertically installed. As will bedescribed later, the heater 207 functions as an activation mechanism(i.e., an excitation unit) configured to thermally activate (or excite)gas.

A reaction tube 203 constituting a reaction vessel (i.e., processvessel) is disposed in the heater 207 in a concentric relationship withthe heater 207. The reaction tube 203 is made of heat resistant materialsuch as quartz (SiO₂) or silicon carbide (SiC) and has a cylindricalshape with its upper end closed and its lower end opened. A processchamber 201 is formed in a hollow cylindrical portion of the reactiontube 203. The process chamber 201 is configured to accommodate aplurality of wafers 200 as substrates. The wafers 200 are horizontallystacked in multiple stages along a vertical direction in a boat 217,which will be described later.

Nozzles 249 a and 249 b are installed in the process chamber 201 topenetrate through a lower portion of the reaction tube 203. Gas supplypipes 232 a and 232 b are connected to the nozzles 249 a and 249 b,respectively. A gas supply pipe 232 c is connected to the gas supplypipe 232 b. In the manner as described above, the two nozzles 249 a and249 b and the three gas supply pipes 232 a to 232 c are installed to thereaction tube 203 and are configured to supply plural kinds of gasesinto the process chamber 201.

However, the processing furnace 202 of the present embodiment is notlimited to the configuration as described above. For example, a manifoldmade of metal and configured to support the reaction tube 203 may beinstalled under the reaction tube 203. Each of the nozzles may beinstalled to penetrate through a sidewall of the manifold. In this case,an exhaust pipe 231, which will be described later, may be furtherinstalled in the manifold. Alternatively, the exhaust pipe 231 may beinstalled to a lower portion of the reaction tube 203, rather than themanifold. A furnace opening portion of the processing furnace 202 may bemade of metal and the nozzles and the like may be installed to themetal-made furnace opening portion.

Mass flow controllers (MFC) 241 a to 241 c, which are flow ratecontrollers (i.e., flow rate control units), and valves 243 a to 243 c,which are opening/closing valves, are sequentially installed in the gassupply pipes 232 a to 232 c from corresponding upstream sides. Gassupply pipes 232 d and 232 e which supply an inert gas are connected,respectively, to the gas supply pipes 232 a and 232 b at more downstreamsides than the valves 243 a and 243 b. Mass flow controllers (MFC) 241 dand 241 e, which are flow rate controllers (i.e., flow rate controlunits), and valves 243 d and 243 e, which are opening/closing valves,are sequentially installed to the gas supply pipes 232 d and 232 e fromcorresponding upstream sides.

The nozzles 249 a and 249 b are connected to end portions of the gassupply pipes 232 a and 232 b, respectively. As illustrated in FIG. 2,the nozzles 249 a and 249 b are disposed in an annular space between aninner wall of the reaction tube 203 and the wafers 200 such that thenozzles 249 a and 249 b extend upward along a stacked direction of thewafers 200 from a lower portion of the inner wall of the reaction tube203 to an upper portion thereof. Specifically, the nozzles 249 a and 249b are installed along a wafer arrangement region in which the wafers 200are arranged and in a region that horizontally surrounds the waferarrangement region at a side of the wafer arrangement region. Thenozzles 249 a and 249 b are configured as L-shaped nozzles, and theirhorizontal portions are installed to penetrate a lower sidewall of thereaction tube 203 while their vertical portions are installed to ascendat least from one end portion to the other end portion of the waferarrangement region. Gas supply holes 250 a and 250 b for supplying gasare formed on side surfaces of the nozzles 249 a and 249 b,respectively. Each of the gas supply holes 250 a and 250 b are openedtoward a center of the reaction tube 203 to allow the gas to be suppliedtoward the wafers 200. A plurality of gas supply holes 250 a and aplurality of gas supply holes 250 b may be installed at a predeterminedopening pitch from a lower portion to an upper portion of the reactiontube 203. An opening area of each of the gas supply holes 250 a and 250b may be identical.

As described above, in the present embodiment, gas is transferredthrough the nozzles 249 a and 249 b which are disposed in thevertically-elongated annular space, that is, a cylindrical space,defined by the inner wall of the reaction tube 203 and end portions ofthe stacked wafers 200. The gas is initially injected into the reactiontube 203, near the wafers 200, through the gas supply holes 250 a and250 b formed in the nozzles 249 a and 249 b. Accordingly, the gassupplied into the reaction tube 203 mainly flows within the reactiontube 203 in a direction parallel to surfaces of the wafers 200, that is,a horizontal direction. According to the above configuration, the gascan be uniformly supplied to the respective wafers 200, which makes athickness of a thin film formed on each of the wafers 200 uniform. Inaddition, the gas flowing over the surfaces of the wafers 200 afterreaction (i.e., residual gas) flows toward an exhaust port (i.e., theexhaust pipe 231) which will be described later. However, the flowdirection of the residual gas is not limited to a vertical direction,but may be appropriately decided depending on a position of the exhaustport.

A precursor gas containing a predetermined element, carbon (C), and ahalogen element and having a chemical bond of the predetermined elementand C, for example, an alkylene halosilane precursor gas containing Sias the predetermined element, an alkylene group, and a halogen group andhaving a chemical bond of Si and C (i.e., Si—C bond); or an alkylhalosilane precursor gas containing Si, an alkyl group, and a halogengroup and having a Si—C bond is supplied from the gas supply pipe 232 ainto the process chamber 201 through the MFC 241 a, the valve 243 a, andthe nozzle 249 a.

In this configuration, the alkylene group is a functional group obtainedby removing two hydrogen (H) atoms from chain-shaped saturatedhydrocarbon (alkane), which is denoted as a chemical formulaC_(n)H_(2n+2), and is an aggregate of atoms that are denoted as achemical formula C_(n)H_(2n). The alkylene group includes a methylenegroup, an ethylene group, a propylene group, a butylene group, or thelike. The alkyl group is a functional group obtained by removing one Hatom from chain-shaped saturated hydrocarbon, which is denoted as achemical formula C_(n)H_(2n+2), and is an aggregate of atoms that aredenoted as a chemical formula C_(n)H_(2n+1). The alkyl group includes amethyl group, an ethyl group, a propyl group, a butyl group, or thelike. The halogen group includes a chloro group, a fluoro group, a bromogroup, or the like. As such, the halogen group includes a halogenelement such as chlorine (Cl), fluorine (F), bromine (Br), or the like.

As the alkylene halosilane precursor gas, it may be possible to use, forexample, a precursor gas containing Si, a methylene group (—CH₂—) as analkylene group, and a chloro group (Cl) as a halogen group (i.e., achlorosilane precursor gas containing a methylene group); or a precursorgas containing Si, an ethylene group (—C₂H₄—) as an alkylene group, anda chloro group (Cl) as a halogen group (i.e., a chlorosilane precursorgas containing an ethylene group). As the chlorosilane precursor gascontaining a methylene group, it may be possible to use, for example, amethylene bis(trichlorosilane) gas, i.e., a bis(trichlorosilyl)methane((SiCl₃)₂CH₂, abbreviation: BTCSM) gas. As the chlorosilane precursorgas containing an ethylene group, it may be possible to use, forexample, an ethylene bis(trichlorosilane) gas, i.e., a1,2-bis(trichlorosilyl)ethane ((SiCl₃)₂C₂H₄, abbreviation: BTCSE) gas.

As depicted in FIG. 13A, BTCSM contains one methylene group as analkylene group in its chemical structural formula (in one molecule).Each of two dangling bonds of the methylene group is bonded to Si, suchthat a Si—C—Si bond is formed.

As depicted in FIG. 13B, BTCSE contains one ethylene group as analkylene group in one molecule. Each of two dangling bonds of theethylene group is bonded to Si, such that a Si—C—C—Si bond is formed.

As the alky halosilane precursor gas, it may be possible to use, forexample, a precursor gas containing Si, a methyl group (—CH₃) as analkyl group, and a chloro group (Cl) as a halogen group (i.e., achlorosilane precursor gas containing a methyl group). As thechlorosilane precursor gas containing a methyl group, it may be possibleto use, for example, a 1,1,2,2-tetrachloro-1,2-dimethyldisilane((CH₃)₂Si₂Cl₄, abbreviation: TCDMDS) gas; a1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH₃)₄Si₂C₂, abbreviation:DCTMDS) gas; a 1-monochloro-1,1,2,2,2-pentamethyldisilane ((CH₃)₅Si₂Cl,abbreviation: MCPMDS) gas; or the like. Unlike the alkylene halosilaneprecursor gas such as the BTCSE gas or the BTCSM gas, the alkylhalosilane precursor gas such as the TCDMDS gas, the DCTMDS gas, or theMCPMDS gas is a gas having a Si—Si bond, that is, a precursor gascontaining a predetermined element and a halogen element and having achemical bond between atoms of the predetermined element.

As depicted in FIG. 13C, TCDMDS contains two methyl groups as alkylgroups in one molecule. Each of dangling bonds of the two methyl groupsis bonded to Si, such that Si—C bonds are formed. TCDMDS is a derivativeof disilane, and has a Si—Si bond. As such, TCDMDS has a Si—Si—C bond inwhich Si and Si are bonded to each other, and Si is bonded to C.

As depicted in FIG. 13D, DCTMDS contains four methyl groups as alkylgroups in one molecule. Each of the dangling bonds of the four methylgroups is bonded to Si, such that Si—C bonds are formed. DCTMDS is aderivative of disilane, and has a Si—Si bond. As such, DCTMDS has aSi—Si—C bond in which Si and Si are bonded to each, other and Si isbonded to C.

As depicted in FIG. 13E, MCPMDS contains five methyl groups as alkylgroups in one molecule. Each of the dangling bonds of the five methylgroups is bonded to Si, such that Si—C bonds are formed. MCPMDS is aderivative of disilane, and has a Si—Si bond. As such, MCPMDS has aSi—Si—C bond in which Si and Si are bonded to each other, and Si isbonded to C. Unlike BTCSM, BTCSE, TCDMDS, and DCTMDS, MCPMDS has anasymmetry structure in which the methyl groups and the chloro groupsurrounding Si are asymmetrically arranged in one molecule (in thechemical structural formula). As described above, in the presentembodiment, it may be possible to use not only a precursor gas having asymmetric chemical structural formula as illustrated in FIGS. 13A to 13Dbut also a precursor gas having an asymmetric chemical structuralformula.

The alkylene halosilane precursor gas such as the BTCSM gas or the BTCSEgas, or the alkyl halosilane precursor gas such as the TCDMDS gas, theDCTMDS gas, or the MCPMDS gas may be a precursor gas which contains atleast two Si atoms in one molecule, contains C and Cl, and has Si—Cbonds. In a substrate processing procedure, which will be describedlater, this gas acts as a Si source and a C source. The BTCSM gas andthe BTCSE gas may be referred to as an alkylene chlorosilane precursorgas. The TCDMDS gas, the DCTMDS gas, and the MCPMDS gas may be referredto as an alkyl chlorosilane precursor gas.

In the present disclosure, the precursor gas refers to a precursor in agaseous state, for example, a gas obtained by vaporizing a precursorwhich is in a liquid state under room temperature and atmosphericpressure, or a precursor which is in a gaseous state under roomtemperature and atmospheric pressure. When the term “precursor” is usedherein, it may refer to “a liquid precursor in a liquid state,” “aprecursor gas in a gaseous state,” or both of them. In the case of usinga liquid precursor in a liquid state under room temperature andatmospheric pressure, such as BTCSM or the like, the liquid precursor isvaporized by a vaporization system, such as a vaporizer or a bubbler,and is supplied as a precursor gas (e.g., a BTCSM gas or the like).

A precursor gas containing a predetermined element, for example, ahalosilane precursor gas containing Si as a predetermined element and ahalogen element, is supplied from the gas supply pipe 232 a into theprocess chamber 201 through the MFC 241 a, the valve 243 a, and thenozzle 249 a.

The halosilane precursor is a silane precursor having a halogen group.The halogen group includes a chloro group, a fluoro group, a bromogroup, an iodine group, and the like. As such, the halogen groupincludes a halogen element such as chlorine (Cl), fluorine (F), bromine(Br), iodine (I), or the like. The halosilane precursor may be one kindof halide.

As the halosilane precursor gas, for example, a precursor gas containingSi and Cl (i.e., a chlorosilane precursor gas). As the chlorosilaneprecursor gas, it may be possible to use, for example, ahexachlorodisilane (Si₂Cl₆, abbreviation: HCDS) gas. In the case ofusing a liquid precursor, such as HCDS or the like, which is in a liquidstate under room temperature and atmospheric pressure, the liquidprecursor is vaporized by a vaporization system such as a vaporizer or abubbler, and is supplied as a precursor gas (e.g., an HCDS gas).

A reaction gas, for example, a nitrogen (N)-containing gas, whichdiffers in chemical structure (e.g., molecular structure) from theprecursor gas, may be supplied from the gas supply pipe 232 b into theprocess chamber 201 through the MFC 241 b, the valve 243 b, and thenozzle 249 b. As the nitrogen-containing gas, it may be possible to use,for example, a hydrogen nitride-based gas. In a substrate processingprocedure, which will be described later, the nitrogen-containing gasacts as a nitriding gas, that is, an N source. As the hydrogennitride-based gas, it may be possible to use, for example, an ammonia(NH₃) gas.

Furthermore, a reaction gas, for example, an oxygen (O)-containing gas,which differs in chemical structure from the precursor gas, may besupplied from the gas supply pipe 232 b into the process chamber 201through the MFC 241 b, the valve 243 b, and the nozzle 249 b. In asubstrate processing procedure, which will be described later, theoxygen-containing gas acts as an oxidizing gas, that is, an O source. Asthe oxygen-containing gas, it may be possible to use, for example, anoxygen (O₂) gas.

Moreover, a reaction gas, for example, an N- and C-containing gas, whichdiffers in chemical structure from the precursor gas, may be suppliedfrom the gas supply pipe 232 b into the process chamber 201 through theMFC 241 b, the valve 243 b, and the nozzle 249 b. As the N- andC-containing gas, it may be possible to use, for example, an amine-basedgas.

The amine-based gas is gaseous amine, for example, a gas which isobtained by vaporizing amine which is in a liquid state under roomtemperature and atmospheric pressure or a gas which contains an aminegroup such as amine or the like which is in a gaseous state under roomtemperature and atmospheric pressure. The amine-based gas contains aminesuch as ethylamine, methylamine, propylamine, isopropylamine,butylamine, isobutylamine, or the like. As used herein, the term “amine”is a generic name of compounds in which a hydrogen atom in ammonia (NH₃)is substituted with a hydrocarbon group such as an alkyl group or thelike. Amine contains a hydrocarbon group such as an alkyl group or thelike as a ligand containing C atoms, i.e., an organic ligand. Theamine-based gas may be referred to as a Si-free gas since it containsthree elements C, N, and H while not containing Si. The amine-based gasmay be referred to as a Si-free and metal-free gas since it does notcontain Si and metal. The amine-based gas may be a substance consistingof only three elements C, N, and H. The amine-based gas acts as an Nsource and as a C source in a substrate processing procedure, which willbe described later. The term “amine” as used herein refers to“amine in aliquid state,” an “amine-based gas in a gaseous state,” or both of them.

As the amine-based gas, it may be possible to use, for example, atriethylamine ((C₂H₅)₃N, abbreviation: TEA) gas, in which the number ofC-containing ligands (i.e., ethyl group) in the chemical structuralformula (in one molecule) is two or more and the number of C atoms inone molecule is larger than the number of N atoms. In the case of usingamine such as TEA or the like which is in a liquid state under roomtemperature and atmospheric pressure, the amine in a liquid state isvaporized by a vaporization system such as a vaporizer or a bubbler, andis supplied as an N- and C-containing gas (e.g., a TEA gas).

A reaction gas, for example, a borazine-ring-skeleton-freeboron-containing gas, which differs in chemical structure from theprecursor gas, may be supplied from the gas supply pipe 232 b into theprocess chamber 201 through the MFC 241 b, the valve 243 b, and thenozzle 249 b. As the borazine-ring-skeleton-free boron-containing gas,it may be possible to use, for example, a borane-based gas.

The borane-based gas refers to a borane compound in a gaseous state, forexample, a gas obtained by vaporizing a borane compound in a liquidstate under room temperature and atmospheric pressure, a borane compoundin a gaseous state under room temperature and atmospheric pressure, orthe like. The borane compound includes a haloborane compound containingB and a halogen element, for example, a chloroborane compound containingB and Cl. Further, the borane compound includes borane (borohydride)such as monoborane (BH₃), diborane (B₂H₆) or the like, or a boranecompound (borane derivative) in which H of borane is substituted withanother element or the like. The borane-based gas acts as a B source ina substrate processing procedure, which will be described later. As theborane-based gas, it may be possible to use, for example, atrichloroborane (BCl₃) gas. The BCl₃ gas is a boron-containing gas whichdoes not contain a borazine compound, which will be described later,that is, a non-borazine-based boron-containing gas.

In addition, a reaction gas, for example, aborazine-ring-skeleton-containing gas, which differs in chemicalstructure from the precursor gas, may be supplied from the gas supplypipe 232 b into the process chamber 201 through the MFC 241 b, the valve243 b, and the nozzle 249 b. As the borazine-ring-skeleton-containinggas, it may be possible to use, for example, a gas containing a borazinering skeleton and an organic ligand, that is, an organic borazine-basedgas.

As the organic borazine-based gas, it may be possible to use, forexample, a gas containing an alkyl borazine compound which is an organicborazine compound. The organic borazine-based gas may be referred to asa borazine compound gas or a borazine-based gas.

As used herein, borazine is a heterocyclic compound composed of threeelements, B, N, and H. Borazine may be denoted as a composition formulaof B₃H₆N₃ and may be denoted as a chemical structural formulaillustrated in FIG. 14A. The borazine compound is a compound including aborazine ring skeleton (also referred to as a “borazine skeleton”),which constitutes a borazine ring containing three B atoms and three Natoms. The organic borazine compound is a borazine compound containingC, and may also be referred to as a borazine compound containing aC-containing ligand, i.e., an organic ligand. The alkyl borazinecompound is a borazine compound containing an alkyl group and may bereferred to as a borazine compound containing an alkyl group as anorganic ligand. The alkyl borazine compound is a compound in which atleast one of six H atoms contained in borazine is substituted withhydrocarbon containing one or more C atoms, and may be denoted as achemical structural formula illustrated in FIG. 14B. In this case, eachof R₁ to R₆ in the chemical structural formula in FIG. 14B is atom or analkyl group containing one to four C atoms. R₁ to R₆ may be the samekind of an alkyl group or may be different kinds of alkyl groups.However, not all of R₁ to R₆ should be H. The alkyl borazine compoundmay refer to a substance including a borazine ring skeleton, whichconstitutes a borazine ring, and contains B N, H, and C. Further, thealkyl borazine compound may refer to a substance including a borazinering skeleton and containing an alkyl ligand. In addition, each of R₁ toR₆ may be an H atom, or an alkenyl group or an alkynyl group containingone to four C atoms, R₁ to R₆ may be the same kind of an alkenyl groupor an alkynyl group, or may be different kinds of alkenyl groups oralkynyl groups. However, not all of R₁ to R₆ should be H.

The borazine-based gas acts as a B source, a N source, and a C source ina substrate processing procedure, which will be described later.

As the borazine-based gas, it may be possible to use, for example, ann,n′,n″-trimethylborazine (abbreviation: TMB) gas; ann,n′,n″-triethylborazinea (abbreviation: TEB) gas; ann,n′,n″-tri-n-propylborazine (abbreviation: TPB) gas; ann,n′,n″-triisopropylborazine (abbreviation: TIPB) gas; ann,n′,n″-tri-n-butylborazine (abbreviation: TBB) gas; ann,n′,n″-triisobutylborazine (abbreviation: TIBB) gas, or the like. TMBis a borazine compound in which R₁, R₃, and R₅ of the chemicalstructural formula illustrated in FIG. 14B are H atoms while R₂, R₄, andR₆ of the chemical structural formula are methyl groups. TMB may bedenoted as a chemical structural formula illustrated in FIG. 14C. TEB isa borazine compound in which R₁, R₃, and R₅ of the chemical structuralformula illustrated in FIG. 14B are H atoms while R₂, R₄, and R₆ of thechemical structural formula are ethyl groups. TPB is a borazine compoundin which R₁, R₃, and R₅ of the chemical structural formula illustratedin FIG. 14B are H atoms while R₂, R₄, and R₆ of the chemical structuralformula are propyl groups. TPB may be denoted as a chemical structuralformula illustrated in FIG. 14D. TIPB is a borazine compound in whichR₁, R₃, and R₅ of the chemical structural formula illustrated in FIG.14B are H atoms while R₂, R₄, and R₆ of the chemical structural formulaare isopropyl groups. TIBB is a borazine compound in which R₁, R₃, andR₅ of the chemical structural formula illustrated in FIG. 14B are Hatoms while R₂, R₄, and R₆ of the chemical structural formula areisobutyl groups.

In the case of using a borazine compound such as TMB or the like, whichis in a liquid state under room temperature and atmopspheric pressure,the borazine compound in a liquid state is vaporized by a vaporizationsystem such as a vaporizer or a bubbler, and is supplied as aborazine-based gas (e.g., a TMB gas).

A reaction gas, for example, a carbon-containing gas, which differs inchemical structure from the precursor gas, may be supplied from the gassupply pipe 232 c into the process chamber 201 through the MFC 241 c,the valve 243 c, the gas supply pipe 232 b, and the nozzle 249 b. As thecarbon-containing gas, it may be possible to use, for example, ahydrocarbon-based gas. The hydrocarbon-based gas may be a substanceconsisting of only two elements C and H. The hydrocarbon-based gas actsas a C source in a substrate processing procedure, which will bedescribed later. As the hydrocarbon-based gas, it may be possible touse, for example, a propylene (C₃H₆) gas.

An inert gas, for example, a nitrogen (N₂) gas, is supplied from the gassupply pipes 232 d and 232 e into the process chamber 201 through theMFCs 241 d and 241 e, the valves 243 d, and 243 e, the gas supply pipes232 a and 232 b, and the nozzles 249 a and 249 b.

In the case of supplying the above-described precursor gas from the gassupply pipe 232 a, a precursor gas supply system mainly includes the gassupply pipe 232 a, the MFC 241 a, and the valve 243 a. The precursor gassupply system may also include the nozzle 249 a. The precursor gassupply system may be referred to as a precursor supply system. In thecase of supplying an alkyl halosilane precursor gas from the gas supplypipe 232 a, the precursor gas supply system may be referred to as analkyl halosilane precursor gas supply system or an alkyl halosilaneprecursor supply system. In the case of supplying an alkylene halosilaneprecursor gas from the gas supply pipe 232 a, the precursor gas supplysystem may be referred to as an alkylene halosilane precursor gas supplysystem or an alkylene halosilane precursor supply system. In the case ofsupplying a halosilane precursor gas from the gas supply pipe 232 a, theprecursor gas supply system may be referred to as a halosilane precursorgas supply system or a halosilane precursor supply system.

In the case of supplying a nitrogen-containing gas from the gas supplypipe 232 b, a nitrogen-containing gas supply system mainly includes thegas supply pipe 232 b, the MFC 241 b, and the valve 243 b. Thenitrogen-containing gas supply system may also include the nozzle 249 b.The nitrogen-containing gas supply system may be referred to as anitriding gas supply system or a nitriding agent supply system. In thecase of supplying a hydrogen nitride-based gas from the gas supply pipe232 b, the nitrogen-containing gas supply system may be referred to as ahydrogen nitride-based gas supply system or a hydrogen nitride supplysystem.

In the case of supplying an oxygen-containing gas from the gas supplypipe 232 b, an oxygen-containing gas supply system mainly includes thegas supply pipe 232 b, the MFC 241 b, and the valve 243 b. Theoxygen-containing gas supply system may also include the nozzle 249 b.The oxygen-containing gas supply system may be referred to as anoxidizing gas supply system or an oxidizing agent supply system.

In the case of supplying an N- and C-containing gas from the gas supplypipe 232 b, a nitrogen- and carbon-containing gas supply system mainlyincludes the gas supply pipe 232 b, the MFC 241 b, and the valve 243 b.The nitrogen- and carbon-containing gas supply system may also includethe nozzle 249 b. In the case of supplying an amine-based gas from thegas supply pipe 232 b, the nitrogen- and carbon-containing gas supplysystem may be referred to as an amine-based gas supply system or anamine supply system. The N- and C-containing gas is anitrogen-containing gas or a carbon-containing gas. Thus, anitrogen-containing gas supply system or a carbon-containing gas supplysystem, which will be described later, may include the nitrogen- andcarbon-containing gas supply system.

In the case of supplying a boron-containing gas from the gas supply pipe232 b, a boron-containing gas supply system mainly includes the gassupply pipe 232 b, the MFC 241 b, and the valve 243 b. Theboron-containing gas supply system may also include the nozzle 249 b. Inthe case of supplying a borane-based gas from the gas supply pipe 232 b,the boron-containing gas supply system may be referred to as aborane-based gas supply system or a borane compound supply system. Inthe case of supplying a borazine-based gas from the gas supply pipe 232b, the boron-containing gas supply system may be referred to as aborazine-based gas supply system, an organic borazine-based gas supplysystem, or a borazine compound supply system. The borazine-based gas isan N- and C-containing gas, which is also a nitrogen-containing gas or acarbon-containing gas. Thus, a nitrogen- and carbon-containing gassupply system, a nitrogen-containing gas supply system, or acarbon-containing gas supply system may include the borazine-based gassupply system.

In the case of supplying a carbon-containing gas from the gas supplypipe 232 c, a carbon-containing gas supply system mainly includes thegas supply pipe 232 c, the MFC 241 c and the valve 243 c. Thecarbon-containing gas supply system may also include the nozzle 249 bdisposed at a more downstream side of a connection portion of the gassupply pipe 232 b and the gas supply pipe 232 c. In the case ofsupplying a hydrocarbon-based gas from the gas supply pipe 232 c, thecarbon-containing gas supply system may be referred to as ahydrocarbon-based gas supply system or a hydrocarbon supply system.

One or all of the nitrogen-containing gas supply system, theoxygen-containing gas supply system, the nitrogen- and carbon-containinggas supply system, the boron-containing gas supply system, and thecarbon-containing gas supply system may be referred to as a reaction gassupply system.

An inert gas supply system mainly includes the gas supply pipes 232 dand 232 e, the MFCs 241 d and 241 e, and the valves 243 d and 243 e. Theinert gas supply system may be referred to as a purge gas supply systemor a carrier gas supply system.

An exhaust pipe 231 for exhausting an internal atmosphere of the processchamber 201 is installed to the reaction tube 203. A vacuum exhaustdevice, for example, a vacuum pump 246, is connected to the exhaust pipe231 via a pressure sensor 245, which is a pressure detector (i.e.,pressure detecting unit) for detecting an internal pressure of theprocess chamber 201, and an APC (Auto Pressure Controller) valve 244,which is a pressure regulator (i.e., pressure regulating unit). The APCvalve 244 is configured to perform or stop vacuum exhaust in the processchamber 201 by opening or closing the valve while the vacuum pump 246 isactuated and is also configured to regulate the internal pressure of theprocess chamber 201 by adjusting an opening degree of the valve pursuantto pressure information detected by the pressure sensor 245 while thevacuum pump 246 is actuated. An exhaust system mainly includes theexhaust pipe 231, the APC valve 244, and the pressure sensor 245. Theexhaust system may also include vacuum pump 246. In addition, the APCvalve 244 constitutes a part of an exhaust flow path of the exhaustsystem. The APC valve 244 serves not only as a pressure regulator butalso as an exhaust flow path opening/closing unit, that is, an exhaustvalve, which can block and seal the exhaust flow path of the exhaustsystem.

A seal cap 219, which serves as a furnace opening cover configured tohermetically seal a lower end opening of the reaction tube 203, isinstalled under the reaction tube 203. The seal cap 219 is configured tomake contact with the lower end of the reaction tube 203 at a lower sidein the vertical direction. The seal cap 219 is made of metal such as,for example, stainless steel or the like, and is formed in a disc shape.An O-ring 220, which is a seal member making contact with the lower endportion of the reaction tube 203, is installed on an upper surface ofthe seal cap 219. A rotation mechanism 267 configured to rotate a boat217, which will be described later, is installed at a side of the sealcap 219 opposite to the process chamber 201. A rotation shaft 255 of therotation mechanism 267, which penetrates through the seal cap 219, isconnected to the boat 217. The rotation mechanism 267 is configured torotate the wafers 200 by rotating the boat 217. The seal cap 219 isconfigured to be vertically moved up and down by a boat elevator 115which is an elevator mechanism vertically installed outside the reactiontube 203. The boat elevator 215 is configured to load and unload theboat 217 into and from the process chamber 201 by moving the seal cap219 up and down. As such, the boat elevator 115 is configured as atransfer device (i.e., transfer mechanism) that transfers the boat 217,ultimately, the wafers 200, into and out of the process chamber 201.

The boat 217 serving as a substrate support is configured to support aplurality of wafers 200, for example, 25 to 200 wafers, in such a statethat the wafers 200 are arranged in a horizontal posture and in multiplestages along a vertical direction, with the centers of the wafers 200concentrically aligned, to be spaced-apart from one another. The boat217 is made of heat resistant material such as quartz or SiC. Heatinsulating plates 218 made of heat resistant material such as quartz orSiC are installed below the boat 217 in a horizontal posture and inmultiple stages. With the above configuration, it is hard for heatgenerated from the heater 207 to be transferred to the seal cap 219.However, the present embodiment is not limited to the above-describedconfiguration. For example, instead of installing the heat insulatingplates 218 below the boat 217, a heat insulating tube as a tubularmember made of heat resistant material such as quartz or SiC may beinstalled below the boat 217.

A temperature sensor 263 serving as a temperature detector is installedin the reaction tube 203. Based on temperature information detected bythe temperature sensor 263, a state of supplying electric power to theheater 207 is adjusted such that the interior of the process chamber 201has a desired temperature distribution. Similar to the nozzles 249 a and249 b, the temperature sensor 263 is formed in an L-shape. Thetemperature sensor 263 is installed along the inner wall of the reactiontube 203.

As illustrated in FIG. 3, a controller 121, which is a control unit (orcontrol part), may be configured as a computer including a centralprocessing unit (CPU) 121 a, a random access memory (RAM) 121 b, amemory device 121 c, and an I/O port 121 d. The RAM 121 b, the memorydevice 121 c, and the I/O port 121 d are configured to exchange datawith the CPU 121 a via an internal bus 121 e. An input/output device 122formed, for example, of a touch panel or the like, is connected to thecontroller 121.

The memory device 121 c is configured with, for example, a flash memory,a hard disc drive (HDD), or the like. A control program for controllingoperations of a substrate processing apparatus or a process recipe, inwhich a sequence or condition for processing a substrate to be describedlater is written, is readably stored in the memory device 121 c. Also,the process recipe functions as a program for the controller 121 toexecute each sequence in the substrate processing procedure, which willbe described later, to obtain a predetermined result. Hereinafter, sucha process recipe or control program may be generally referred to as “aprogram.” Also, when the term “program” is used herein, it may indicatea case of including only a process recipe, a case of including only acontrol program, or a case of including both a process recipe and acontrol program. In addition, the RAM 121 b is configured as a memoryarea (or a work area) in which a program or data read by the CPU 121 ais temporarily stored.

The I/O port 121 d is connected to the MFCs 241 a to 241 e, the valves243 a to 243 e, the pressure sensor 245, the APC valve 244, the vacuumpump 246, the heater 207, the temperature sensor 263, the rotationmechanism 267, the boat elevator 115, and the like.

The CPU 121 a is configured to read and execute the control program fromthe memory device 121 c. The CPU 121 a also reads the process recipefrom the memory device 121 c according to an input of an operationcommand from the input/output device 122. In addition, the CPU 121 a isconfigured to control the flow rate adjusting operation of various kindsof gases by the MFCs 241 a to 241 e, the opening/closing operation ofthe valves 243 a to 243 e, the opening/closing operation of the APCvalve 244, the pressure regulating operation by the APC valve 244 basedon the pressure sensor 245, the start/stop operation of the vacuum pump246, the temperature adjusting operation by the heater 207 based on thetemperature sensor 263, the rotation and rotation speed adjustingoperation of the boat 217 by the rotation mechanism 267, the elevationoperation of the boat 217 by the boat elevator 115, and the like,according to contents of the read process recipe.

Moreover, the controller 121 is not limited to being configured as adedicated computer but may be configured as a general-purpose computer.For example, the controller 121 according to the present embodiment maybe configured by preparing an external memory device 123 (for example, amagnetic tape, a magnetic disc such as a flexible disc or a hard disc,an optical disc such as a CD or DVD, a magneto-optical disc such as anMO, a semiconductor memory such as a USB memory or a memory card), inwhich the program is stored, and installing the program on thegeneral-purpose computer using the external memory device 123. Also,means for providing the program to the computer is not limited to thecase in which the program is provided through the external memory device123. For example, the program may be supplied using communication meanssuch as the Internet or a dedicated line, rather than through theexternal memory device 123. Also, the memory device 121 c or theexternal memory device 123 is configured as a non-transitorycomputer-readable recording medium. Hereinafter, the means for supplyingthe program will be simply referred to as a “recording medium.” Inaddition, when the term “recording medium” is used herein, it mayinclude a case of including only the memory device 121 c, a case ofincluding only the external memory device 123, or a case of includingboth the memory device 121 c and the external memory device 123

(2) Substrate Processing Procedure

An example of a procedure for forming a thin film on a substrate, whichis one of the procedures for manufacturing a semiconductor device byusing the above described substrate processing apparatus, is describedbelow with reference to FIG. 4. In the following descriptions, theoperations of the respective units or parts constituting the substrateprocessing apparatus are controlled by the controller 121.

In a film forming sequence as illustrated in FIG. 4, a siliconcarbonitride film (SiCN film) is formed on a wafer 200 as a substratedisposed in the process chamber 201 by performing a predetermined numberof times (e.g., n times) a cycle that non-simultaneously (i.e., withoutsynchronization) performs a step of supplying a BTCSM gas as a precursorgas to the wafer 200; a step of exhausting the BTCSM gas in the processchamber 201 through the exhaust system; a step of supplying an NH₃ gasas a reaction gas differing in chemical structure from the BTCSM gas tothe wafer 200 and confining the NH₃ gas in the process chamber 201 whilethe exhaust system is closed; and a step of exhausting the NH₃ gas inthe process chamber 201 through the exhaust system while the exhaustsystem is opened.

In the above operation, a target pressure (i.e., to-be-reached pressure)provided in the process chamber 201 at the step of confining the NH₃ gasin the process chamber 201 is set to be higher than a target pressureprovided in the process chamber 201 at the step supplying the BTCSM gas.The “pressure” illustrated in FIG. 4 is an internal pressure (i.e.,total pressure) of the process chamber 201 indicated with an arbitraryunit (a.u.). In the “set pressure” illustrated in FIG. 4, the intervalindicated with a dot line refers to an interval in which the APC valve244 is fully opened or fully closed. As such, the period indicated withthe dot line refers to a period in which the internal pressure of theprocess chamber 201 is not controlled, that is, the APC valve 244 is notfeedback-controlled.

To control the internal pressure, in the film forming sequence shown inFIG. 4, as an example, the opening degree of the exhaust flow path ofthe exhaust system at the step of confining the NH₃ gas in the processchamber 201 is set to be smaller than the opening degree of the exhaustflow path at the step of supplying the BTCSM gas. Specifically, at thestep of confining the NH₃ gas in the process chamber 201, the APC valve244 installed in the exhaust system is fully closed so as to completelyclose the exhaust flow path of the exhaust system with no gap, that is,so as to seal the exhaust system. For example, in the film formingsequence shown in FIG. 4, at the step of confining the NH₃ gas in theprocess chamber 201, the NH₃ gas is continuously supplied into theprocess chamber 201 such that the internal pressure of the processchamber 201 continues to increase.

As used herein, the phrase “performing a cycle a predetermined number oftimes” means that that the cycle is performed once or a plurality oftimes. In other words, the phrase may also mean that the cycle isperformed one or more times. FIG. 4 illustrates an example in which thecycle is repeated n times.

As used herein, the term “wafer” may refer to “a wafer itself” or “awafer and a laminated body (a collected body) of predetermined layers orfilms formed on a surface of the wafer” (i.e., a wafer includingpredetermined layers or films formed on its surface may be referred toas a wafer). In addition, as used herein, the phrase “a surface of awafer” may refer to “a surface (or an exposed surface) of a waferitself” or “a surface of a predetermined layer or film formed on awafer, i.e., an uppermost surface of the wafer, which is a laminatedbody.”

As such, as used herein, the phrase “a predetermined gas is supplied toa wafer” may mean that “a predetermined gas is directly supplied to asurface (or an exposed surface) of a wafer itself” or that “apredetermined gas is supplied to a layer or a film formed on a wafer,i.e., on an uppermost surface of a wafer as a laminated body.” Also, asused herein, the phrase “a predetermined layer (or film) is formed on awafer” may mean that “a predetermined layer (or film) is directly formedon a surface (or an exposed surface) of a wafer itself” or that “apredetermined layer (or film) is formed on a layer or a film formed on awafer, i.e., on an uppermost surface of a wafer as a laminated body.”

In addition, the term “substrate” as used herein may be synonymous withthe term “wafer” and, in this case, the terms “wafer” and “substrate”may be used interchangeably in the above descriptions.

(Wafer Charge and Boat Load)

When the plurality of wafers 200 is charged on the boat 217 (i.e., wafercharge), as illustrated in FIG. 1, the boat 217 supporting the pluralityof wafers 200 is lifted by the boat elevator 115 and is loaded into theprocess chamber 201 (i.e., boat load). In this state, the seal cap 219seals the lower end of the reaction tube 203 through the O-ring 220.

(Pressure Adjustment and Temperature Adjustment)

An internal pressure of the process chamber 201, that is, of the spacein which the wafers 200 exist is vacuum-exhausted (i.e.,pressure-reducing exhaust) by the vacuum pump 246 to reach a desiredpressure (or a desired vacuum level). In this operation, the internalpressure of the process chamber 201 is measured by the pressure sensor245. The APC valve 244 is feedback-controlled based on the measuredpressure information. The vacuum pump 246 may be continuously activatedat least until the processing on the wafers 200 is completed. The wafers200 in the process chamber 201 are heated by the heater 207 to a desiredtemperature. In this operation, the state of supplying electric power tothe heater 207 is feedback-controlled based on temperature informationdetected by the temperature sensor 263 such that the interior of theprocess chamber 201 reaches a desired temperature distribution. Inaddition, the heating of the interior of the process chamber 201 by theheater 207 may be continuously performed at least until the processingon the wafers 200 is completed. The boat 217 and the wafers 200 begin tobe rotated by the rotation mechanism 267. Furthermore, the rotation ofthe boat 217 and the wafers 200 by the rotation mechanism 267 may becontinuously performed at least until the processing on the wafers 200is completed.

(SiCN Film Forming Procedure)

Next, the following two steps, i.e., Steps 1 and 2, are sequentiallyperformed.

[Step 1]

(BTCSM Gas Supply)

While the APC valve 244 is opened at a predetermined opening degree, thevalve 243 a is opened to flow a BTCSM gas through the gas supply pipe232 a. A flow rate of the BTCSM gas is adjusted by the MFC 241 a. Theflow rate-adjusted BTCSM gas is supplied through the gas supply holes250 a into the process chamber 201, and is exhausted through the exhaustpipe 231. As such, the BTCSM gas is supplied to the wafers 200. In thisoperation, the valve 243 d is opened to flow a N₂ gas through the gassupply pipe 232 d. A flow rate of the N₂ gas is adjusted by the MFC 241d. The flow rate-adjusted N₂ gas is supplied into the process chamber201 together with the BTCSM gas, and is exhausted through the exhaustpipe 231.

In order to prevent infiltration of the BTCSM gas into the nozzle 249 b,the valve 243 e is opened to flow a N₂ gas to flow through the gassupply pipe 232 e. The N₂ gas is supplied into the process chamber 201through the gas supply pipe 232 b and the nozzle 249 b, and is exhaustedthrough the exhaust pipe 231.

In the above operation, the supply flow rate of the BTCSM gas controlledby the MFC 241 a is set to fall within a range, for example, of 1 to2,000 sccm, specifically, 10 to 1,000 sccm. The supply flow rate of theN₂ gas controlled by the MFC 241 d or 241 e is set to fall within arange, for example, of 100 to 10,000 sccm. As the BTCSM gas is suppliedinto the process chamber 201, the internal pressure of the processchamber 201 begins to increase. Thereafter, if the internal pressure ofthe process chamber 201 reaches a predetermined pressure within a range,for example, of 1 to 2,666 Pa, specifically, 67 to 1,333 Pa, the openingdegree of the APC valve 244 is appropriately adjusted such that theinternal pressure of the process chamber 201 is maintained to beconstant. A time period for supplying the BTCSM gas into the processchamber 201, in other words, a gas supply time (i.e., an irradiationtime) for the wafers 200, is set to fall within a range, for example, of1 to 120 seconds, specifically, 1 to 60 seconds. A temperature of theheater 207 is set such that a temperature of the wafers 200 falls withina range, for example, of 400 to 800 degrees C., specifically, 500 to 700degrees C., more specifically, 600 to 700 degrees C.

When the temperature of the wafers 200 is less than 400 degrees C., itis hard for BTCSM to be chemically adsorbed onto the wafers 200, andthus, a practical film forming rate may not be obtained. This problemcan be solved by increasing the temperature of the wafers 200 to be 400degrees C. or higher. By setting the temperature of the wafers 200 to be500 degrees C. or higher, BTCSM can be sufficiently adsorbed onto thewafers 200, which may lead to obtaining a considerably sufficient filmforming rate. By setting the temperature of the wafers 200 to be 600degrees C. or higher, more specifically, 650 degrees C. or higher, BTCSMgas can be more sufficiently adsorbed onto the wafers 200, which maylead to obtaining a higher film forming rate.

If the temperature of the wafers 200 exceeds 800 degrees C., a CVDreaction becomes intensive (in other words, a gas phase reaction becomesdominant). Thus, film thickness uniformity may be hard to control andoften deteriorate. By setting the temperature of the wafers 200 to be800 degrees C. or lower, such deterioration of the film thicknessuniformity can be suppressed and, thus, the film thickness uniformitycan be controlled. In particular, a surface reaction becomes dominant bysetting the temperature of the wafers 200 to be 700 degrees C. or lowerand, thus, it becomes possible to secure the film thickness uniformityand control the film thickness uniformity.

Accordingly, the temperature of the wafers 200 may be set to fall withina range of 400 to 800 degrees C., specifically, 500 to 700 degrees C.,more specifically, 600 to 700 degrees C. The BTCSM gas is low indegradability (or low in reactivity) and a pyrolysis temperature of theBTCSM gas is high. Therefore, even if a film is formed in a relativelyhigh temperature zone, for example, of 650 to 800 degrees C., it ispossible to suppress generation of an excessive gas phase reaction andto suppress resultant generation of particles.

By supplying the BTCSM gas to the wafers 200 under the above conditions,a first layer, for example, a Si-containing layer containing C and Cland having a thickness, for example, of less than one atomic layer toseveral atomic layers is formed on the wafer 200 (or a base film of itssurface). The Si-containing layer containing C and Cl is a layerincluding a Si—C bond. The Si-containing layer containing C and Cl maybe a Si layer containing C and Cl, an adsorption layer of the BTCSM gas,or both of them.

Herein, the phrase “a Si layer containing C and Cl” is a generic namewhich encompasses a continuous layer and a discontinuous layer that areformed of Si and contain C and Cl, and a Si thin film containing C andCl which is formed by laminating the above layers. The continuous layerthat is formed of Si and contains C and Cl may be referred to as a Sithin film containing C and Cl. In addition, Si that constitutes the Silayer containing C and Cl includes Si whose bond to C and Cl iscompletely broken, in addition to Si whose bond to C and Cl is notcompletely broken.

An adsorption layer of the BTCSM gas includes a continuous adsorptionlayer in which gas molecules of the BTCSM gas are continuous, and adiscontinuous adsorption layer in which gas molecules of the BTCSM gasare discontinuous. In other words, the adsorption layer of the BTCSM gasmay include an adsorption layer formed of BTCSM molecules and having athickness of one molecular layer or less than one molecular layer. TheBTCSM molecules that constitute the adsorption layer of the BTCSM gasinclude a molecule in which a bond between Si and C is partially brokenand a molecule in which a bond between Si and Cl is partially broken. Assuch, the adsorption layer of the BTCSM gas may include a physicaladsorption layer of the BTCSM gas, a chemical adsorption layer of theBTCSM gas, or both of them.

Herein, a layer having a thickness of less than one atomic layer refersto a discontinuously formed atomic layer. A layer having a thickness ofone atomic layer refers to a continuously formed atomic layer. A layerhaving a thickness of less than one molecular layer refers to adiscontinuously formed molecular layer. A layer having a thickness ofone molecular layer refers to a continuously formed molecular layer. ASi-containing layer containing C and Cl may include both a Si layercontaining C and Cl and an adsorption layer of a BTCSM gas. As describedabove, the Si-containing layer containing C and Cl is described with theterms such as “one atomic layer,” “several atomic layers,” and the like.

Under a condition in which the BTCSM gas is autolyzed (or pyrolyzed),that is, a condition in which a pyrolysis reaction of the BTCSM gasoccurs, Si is deposited on the wafer 200 to form the Si layer containingC and Cl. Under a condition in which the BTCSM gas is not autolyzed (orpyrolyzed), that is, a condition in which a pyrolysis reaction of theBTCSM gas does not occur, the BTCSM gas is adsorbed onto the wafer 200to form an adsorption layer of the BTCSM gas. In any of the aboveconditions, at least a portion of the Si—C bonds in the BTCSM gas aremaintained to be unbroken and are introduced into the Si-containinglayer containing C and Cl (i.e., the Si layer containing C and Cl or theadsorption layer of the BTCSM gas). For example, although one of theSi—C bonds, which constitute a Si—C—Si bond in the BTCSM gas, is broken,the other Si—C bond may be maintained to be unbroken and introduced intothe Si layer containing C and Cl. From the viewpoint of increasing afilm forming rate, it may be more advantageous to form the Si layercontaining C and Cl on the wafer 200 than to form the adsorption layerof the BTCSM gas on the wafer 200.

If a thickness of the first layer formed on the wafer 200 exceedsseveral atomic layers, an effect of a modification reaction at followingStep 2, which will be described later, is not to be applied to theentire first layer. On the other hand, a minimum value of the thicknessof the first layer to be formed on the wafer 200 is less than one atomiclayer. Accordingly, the thickness of the first layer may be set to fallwithin a range of less than one atomic layer to several atomic layers.In addition, when the thickness of the first layer is set to be oneatomic layer or less (i.e., one atomic layer or less than one atomiclayer), the effect of the modification reaction at Step 2, which will bedescribed later, can be relatively increased, which can lead toshortening a time required for the modification reaction at Step 2. Itis also possible to shorten a time required for forming the first layerat Step 1. As a result, a processing time per cycle can be shortened,and hence, a total processing time can also be shortened. As such, thefilm forming rate can be increased. In addition, if the thickness of thefirst layer is set to be one atomic layer or less, it is possible tobetter control film thickness uniformity

(Residual Gas Removal)

After the first layer is formed, the valves 243 a, 243 d, and 243 e areclosed to stop the supply of the BTCSM gas and the N₂ gas. In thisoperation, while the exhaust system is opened, the BTCSM gas remainingin the process chamber 201 is exhausted through the exhaust system. FIG.4 illustrates an example where the APC valve 244 is fully opened whenthe exhaust system is opened and the interior of the process chamber 201is vacuum-exhausted to remove from the interior of the process chamber201 the BTCSM gas, which has not reacted or remains after contributingto the formation of the first layer, remaining in the process chamber201. When the exhaust system is opened, the APC valve 244 may not befully opened and may be slightly closed.

As the precursor gas, in addition to the BTCSM gas, it may be possibleto use, for example, a BTCSE gas, a TCDMDS gas, a DCTMDS gas, or anMCPMDS gas. As the inert gas, in addition to the N₂ gas, it may bepossible to use a rare gas such as an Ar gas, a He gas, a Ne gas, a Xegas, or the like.

[Step 2]

(NH₃ Gas Supply)

After Step 1 is completed, an NH₃ gas is supplied to the wafers 200 inthe process chamber 201 while the exhaust system is sealed, to confinethe NH₃ gas in the process chamber 201.

When the exhaust system is sealed, the APC valve 244 is fully closed.When the NH₃ gas is supplied to the wafers 200 in the process chamber201, opening and closing controls of the valves 243 b, 243 d, and 243 eare performed in the same manner as the opening and closing controls ofthe valves 243 b, 243 d, and 243 e that are performed at Step 1. Asupply flow rate of the NH₃ gas controlled by the MFC 241 b is set tofall within a range, for example, of 10 to 10,000 sccm. A supply flowrate of the N₂ gas controlled by the MFCs 241 d or 241 e is set to fallwithin a range, for example, of 100 to 10,000 sccm. A time period forsupplying the NH₃ gas into the process chamber 201, that is, a gassupply time (i.e., an irradiation time), is set to fall within a range,for example, of 1 to 120 seconds, specifically, 1 to 60 seconds. Otherprocessing conditions may be the same as those of Step 1 as describedabove.

By supplying the NH₃ gas into the process chamber 201 while the exhaustsystem is sealed, the NH₃ gas is confined in the process chamber 201.Thus, the internal pressure of the process chamber 201 begins toincrease. By continuously supplying the NH₃ gas into the process chamber201 while the exhaust system is sealed, the internal pressure of theprocess chamber 201 continues to increase. By continuously supplying theNH₃ gas while the exhaust system is sealed, an ultimately-reachedinternal pressure of the process chamber 201, that is, a target internalpressure of the process chamber 201, is set to be higher than the targetinternal pressure of the process chamber 201 available when supplyingthe BTCSM gas at Step 1. Specifically, the target internal pressure(i.e., total internal pressure) of the process chamber 201 is set tofall within a range, for example, of 400 to 5,000 Pa, specifically, 500to 4,000 Pa. In this operation, a partial pressure of the NH₃ gas in theprocess chamber 201 falls within a range, for example, of 360 to 4,950Pa. By setting the internal pressure of the process chamber 201 and thepartial pressure of the NH₃ gas in the process chamber 201 to fallwithin the above high pressure zones, the NH₃ gas supplied into theprocess chamber 201 can be activated efficiently by using heat under anon-plasma condition, even if the internal temperature of the processchamber 201, ultimately, the temperature of the wafers 200, is set tofall within a relatively low temperature range, for example, of 400 to500 degrees C., at Step 2.

By supplying the thermally-activated NH₃ gas to the wafers 200 under theabove-described conditions, at least a portion of the first layer formedon the wafer 200 is nitrided (i.e., modified). As a result of themodification of the first layer, a second layer containing Si, C, and N,that is, a SiCN layer, is formed on the wafers 200. The supply of thethermally activated NH₃ gas under a non-plasma condition can have theabove reaction to occur softly, which in turn can facilitate theformation of the SiCN layer. When the second layer is formed, impuritiessuch as Cl and the like included in the first layer generate a gaseoussubstance containing at least Cl in the course of the modificationreaction of the first layer by the NH₃ gas, and the gaseous substance isexhausted from the interior of the process chamber 201. As such, theimpurities such as Cl and the like included in the first layer areseparated from the first layer by being extracted or desorbed from thefirst layer. Thus, the second layer becomes a layer having fewerimpurities such as Cl and the like than the first layer.

(Residual Gas Removal)

After the second layer is formed, the valves 243 a, 243 d, and 243 e areclosed to stop the supply of the NH₃ gas and the N₂ gas. In thisoperation, while the exhaust system is opened, the NH₃ gas remaining inthe process chamber 201 is exhausted through the exhaust system. FIG. 4illustrates an example, which is similar to that of Step 1, where theAPC valve 244 is fully opened when the exhaust system is opened and theinterior of the process chamber 201 is vacuum-exhausted to remove fromthe interior of the process chamber 201 the NH₃ gas, which has notreacted or remains after contribution to the formation of the secondlayer, or reaction byproduct, remaining in the process chamber 201.Similar to Step 1, when the exhaust system is opened, the APC valve 244may not be fully opened and may be slightly closed.

As the nitrogen-containing gas (i.e., nitriding gas) used as thereaction gas, in addition to the NH₃ gas, it may be possible to use, forexample, a hydrogen nitride-based gas such as a diazene (N₂H₂) gas, ahydrazine (N₂H₄) gas, an N₃H₈ gas, or the like, or a gas containing theabove compounds. As the inert gas, in addition to the N₂ gas, it may bepossible to use a rare gas such as an Ar gas, a He gas, a Ne gas, a Xegas, or the like.

(Performing Cycle Predetermined Number of Times)

A cycle that non-simultaneously performs Steps 1 and 2 as describedabove is performed one or more times (e.g., a predetermined number oftimes) to form a SiCN film having a predetermined composition and apredetermined thickness on the wafer 200. The above cycle may berepeated multiple times. As such, a thickness of the SiCN layer formedper one cycle is set to be smaller than a desired film thickness and theabove cycle may be repeated multiple times until the desired filmthickness is obtained.

In the configuration in which the cycle is performed multiple times, thephrase “a predetermined gas is supplied to the wafer 200” at each stepin at least a second cycle or subsequent cycles may mean that “apredetermined gas is supplied to a layer formed on the wafer 200, thatis, on the uppermost surface of the wafer 200 as a laminated body.” Thephrase “a predetermined layer is formed on the wafer 200” may mean that“a predetermined layer is formed on a layer formed on the wafer 200,that is, on the uppermost surface of the wafer 200 as a laminated body.”The above definitions are the same as those described above. Thedefinitions also apply to each of modifications and other embodiments,which will be described later.

(Purge and Return to Atmospheric Pressure)

The valves 243 d and 243 e are opened. The N₂ gas is supplied into theprocess chamber 201 from each of the gas supply pipes 232 d and 232 e,and is exhausted through the exhaust pipe 231. The N₂ gas serves as apurge gas. Thus, the interior of the process chamber 201 is purged, andresidual gas or reaction byproduct remaining in the process chamber 201is removed from the interior of the process chamber 201 (i.e., purge).Thereafter, the internal atmosphere of the process chamber 201 issubstituted with an inert gas (i.e., inert gas substitution), and theinternal pressure of the process chamber 201 is returned to atmosphericpressure (i.e., return to atmospheric pressure).

(Boat Unload and Wafer Discharge)

The seal cap 219 is moved down by the boat elevator 115 to open thelower end portion of the reaction tube 203. The processed wafers 200supported by the boat 217 is unloaded from the lower end portion of thereaction tube 203 outside of the reaction tube 203 (i.e., boat unload).The processed wafers 200 are then discharged from the boat 217 (i.e.,wafer discharge).

(3) Effects According to the Present Embodiment

According to the present embodiment, one or more effects may beachieved, as follows.

(a) While the exhaust system is sealed, the NH₃ gas is supplied to thewafers 200 in the process chamber 201 and confined in the processchamber 201, which can prevent the NH₃ gas from being discharged fromthe interior of the process chamber 201 before the NH₃ gas is thermallyactivated. Furthermore, it is possible to sufficiently secure a timeperiod for which the NH₃ gas stays in the process chamber 201,ultimately, a heating time required for thermally activating the NH₃gas. Thus, activation of the NH₃ gas is reliably performed. Accordingly,it is possible to promote a reaction of the first layer with the NH₃gas. As a result, a film forming rate of the second layer, that is, afilm forming rate of the SiCN film can be increased. According to thepresent embodiment, although the SiCN film is formed in a relatively lowtemperature zone, for example, of 400 to 500 degrees C., it is easy tohave the first layer to react with the NH₃ gas. Thus, the SiCN film canbe formed at a practical film forming rate. It is also possible toreduce an amount of the NH₃ gas discharged from the interior of theprocess chamber 201 without contributing to the reaction with the firstlayer, which can increase use efficiency of the NH₃ gas and reduce afilm forming cost.

(b) The opening degree of the APC valve 244 when the NH₃ gas is confinedis set to be smaller than the opening degree of the APC valve 244 whenthe BTCSM gas is supplied, such that the target internal pressure of theprocess chamber 201 when the NH₃ gas is confined can be set to be higherthan the target internal pressure of the process chamber 201 when theBTCSM gas is supplied. This configuration can efficiently activate theNH₃ gas confined in the process chamber 201 and further increase thefilm forming rate of the SiCN film.

In particular, when the NH₃ gas is confined, the APC valve 244 is fullyclosed to seal the exhaust system, which can further increase the targetinternal pressure of the process chamber 201 when the NH₃ gas isconfined. Since the exhaust system is sealed when the NH₃ gas isconfined, the internal pressure of the process chamber 201 can beincreased at a high speed and within a short period of time. Thisconfiguration can effectively activate the NH₃ gas confined in theprocess chamber 201 and further increase the film forming rate of theSiCN film.

(c) When the NH₃ gas is confined, the internal pressure of the processchamber 201 can be continuously increased by continuously supplying theNH₃ gas into the process chamber 201. This makes it possible to furtherincrease the target internal pressure of the process chamber 201 whenthe NH₃ gas is confined. As a result, he NH₃ gas supplied into theprocess chamber 201 can be effectively activated, and the film formingrate of the SiCN film can be increased.

By continuously supplying the NH₃ gas into the process chamber 201 whenthe NH₃ gas is confined, it is possible to supplement the NH₃ gasconsumed by the reaction with the first layer, that is, to keep thepartial pressure of the NH₃ gas in the process chamber 201 high. Thismakes it possible to maintain efficiency of a reaction between the firstlayer and the NH₃ gas. As such, reduction in the film forming rate ofthe SiCN film can be suppressed.

(d) By supplying the activated NH₃ gas, impurities such as Cl and thelike can be efficiently extracted or desorbed from the first layer.Thus, the second layer becomes a layer having a low amount ofimpurities. As a result, even if a film is formed in a relatively lowtemperature zone, for example, of 400 to 500 degrees C., concentrationof impurities in the SiCN film can be reduced. Consequently, the SiCNfilm becomes a film having a high resistance to hydrogen fluoride (HF).

(e) The NH₃ gas is activated under a non-plasma atmosphere or anon-plasma condition, by using heat. Thus, when the first layer reactswith the NH₃ gas, at least a portion of the Si—C bonds in the firstlayer can be maintained to be unbroken as they are. This can suppressdesorption of C from the first layer, that is, reduction of Cconcentration in the second layer. As a result, it is possible tosuppress reduction of in-film C concentration in the SiCN film.Consequently, the SiCN film becomes a film having a high HF resistance.

(f) By performing the above cycle a predetermined number of times undera non-plasma condition, plasma damage to the wafer 200 or the SiCN filmformed on the wafer 200 can be avoided. For example, it is possible toavoid a situation that a gate insulation film or the like formed on thewafer 200 is destroyed due to physical damage such as collision ofcharged particles or the like, or a situation that a device structureformed on the wafer 200 is electrically charged and destroyed due tocharging damage. Likewise, it is also possible to avoid plasma damage tothe members disposed in the process chamber 201, which can reducemaintenance cost of the substrate processing apparatus.

(g) By using a halosilane precursor gas such as a BTCSM gas or the likecontaining a plurality of halogen elements (Cl) in one molecule, thefirst layer can be efficiently formed and the film forming rate of theSiCN film can be increased. Furthermore, the consumption of the BTCSMgas that does not contribute to the film formation can be reduced, whichcan lead to reduction in the cost of film forming.

(h) By using the alkylene halosilane precursor gas such as a BTCSM gasor the like which is small in a molecular weight (i.e., molecular size)of an alkylene group contained in one molecule, it is possible tofurther increase the film forming rate and to form a strong film for thefollowing reasons. For example, in the case of using an alkylenehalosilane precursor gas which contains, in one molecule, an alkylenegroup such as a hexylene group or a heptylene group having a largemolecular weight, the alkylene group having a large molecular weight maysometimes cause steric hindrance that inhibits a reaction of Sicontained in the precursor gas, thereby inhibiting formation of thefirst layer. Moreover, if the above alkylene group remains in the firstlayer in a non-decomposed state or an only partially decomposed state,the alkylene group having a large molecular weight may sometimes causesteric hindrance that inhibits the reaction of Si contained in the firstlayer with the NH₃ gas, thereby inhibiting formation of the secondlayer. In contrast, by using an alkylene halosilane precursor gas suchas a BTCSM gas or the like which is small in molecular weight ofalkylene groups contained in one molecule, it is possible to suppressgeneration of the steric hindrance and to promote formation of the firstlayer and the second layer. Consequently, it is possible to increase afilm forming rate and to form a strong film. The same effect can beobtained in the case of using an alkyl halosilane precursor gas such asa TCDMDS gas or the like which is small in molecular weight of alkylgroups contained in one molecule.

(i) By using a precursor gas such as a BTCSM gas or the like containingtwo Si atoms in one molecule, the finally-formed SiCN film becomes afilm in which Si atoms adjoin one another for the following reasons.When the first layer is formed under a condition in which the BTCSM gasis not autolyzed, two Si atoms contained in a BTCSM gas molecule areadsorbed onto the wafer 200 (i.e., a base film of a surface of the wafer200) in a mutually adjoining state. Furthermore, when the first layer isformed under a condition in which the BTCSM gas is autolyzed, two Siatoms contained in a BTCSM gas molecule have a strong tendency to bedeposited on the wafer 200 in a mutually adjoining state. As such, byusing a gas such as a BTCSM gas or the like containing two Si atoms inone molecule, as compared with the case where a gas such as adichlorosilane (SiH₂Cl₂, abbreviation: DCS) gas or the like containingonly one Si atom in one molecule is used, it is possible to make surethat Si atoms contained in the first layer is in a mutually-adjoiningstate. Consequently, the SiCN film becomes a film in which Si atomsadjoin one another. This makes it possible to enhance a HF resistance ofthe film.

(j) By using the alkylene halosilane precursor gas such as a BTCSM gasor the like acting as a Si source and a C source, and the reaction gassuch as an NH₃ gas or the like acting as a N source, that is, by usingtwo kinds of gases, it is possible to form a film containing threeelements, Si, C, and N. In other words, when a film is formed, there isno need to independently supply three kinds of gases, specifically, a Sisource, a C source, and a N source. Accordingly, as compared with thecase where three kinds of gases are used, it is possible to reduce thenumber of gas supply steps by one step, which can shorten a timerequired for one cycle and improve productivity of a film formingprocess. Moreover, as compared with the case where three kinds of gasesare used, the number of gas supply lines can be reduced by one line,which can simplify a structure of a substrate processing apparatus andreduce manufacturing cost or maintenance cost of the substrateprocessing apparatus.

(k) Since the BTCSM gas is low in degradability (or low in reactivity),and its pyrolysis temperature is high, even if a film is formed in arelatively high temperature zone, for example, of 650 to 800 degrees C.,an excessive gas phase reaction can be suppressed. As a result,generation of particles in the process chamber 201 can be suppressed andsubstrate processing quality can be improved.

(l) By non-simultaneously or alternately performing supply steps ofdifferent gases, the gases are allowed to appropriately react under acondition in which a surface reaction is dominant. Consequently, stepcoverage of the SiCN film can be improved and thickness of the film canbe controlled. In addition, generation of an excessive gas phasereaction in the process chamber 201 can be avoided and generation ofparticles can be suppressed.

(m) The above effects may also be achieved in the case where a precursorgas other than the BTCSM gas, which has an Si—C bond, is used as theprecursor gas, the case where a nitrogen-containing gas other than theNH₃ gas is used as the reaction gas, or the case where a gas other thanthe nitrogen-containing gas, for example, a gas containing N and C, anoxygen-containing gas, a boron-containing gas, or a carbon-containinggas, is used as the reaction gas.

(4) Modifications

The film forming sequence according to the present embodiment is notlimited to the sequence illustrated in FIG. 4 and may be modified, aswill be described below.

(Modification 1)

As illustrated in FIG. 5, in the step of supplying the NH₃ gas, thesupply of the NH₃ gas may be stopped before the supply of the N₂ gas isstopped. Thus, in the step of supplying the NH₃ gas, after the supply ofthe NH₃ gas into the process chamber 201 is stopped an internal pressure(i.e., total pressure) of the process chamber 201 filled with the NH₃gas may be continuously increased by continuously supplying the N₂ gasinto the process chamber 201 while the exhaust system is sealed.

A time for supplying the NH₃ gas into the process chamber 201 may be setto fall within a range, for example, of 1 to 60 seconds, specifically, 1to 30 seconds. A time for continuously supplying the N₂ gas into theprocess chamber 201 after the supply of the NH₃ gas is stopped may beset to fall within a range, for example, of 1 to 60 seconds,specifically, 1 to 30 seconds. Other processing procedures andprocessing conditions may be the same as those of the film formingsequence illustrated in FIG. 4. Moreover, in this modification,processing procedures and processing conditions at the step of supplyingthe BTCSM gas may be the same as those of the film forming sequenceillustrated in FIG. 4.

In this modification, the same effects as those of the film formingsequence illustrated in FIG. 4 may be achieved.

According to this modification, it is possible to improve uniformity ofa film thickness and a film quality of the SiCN film between the planesof the wafers 200 and within the plane of each of the wafers 200, forthe following reasons. The N₂ gas supplied into the process chamber 201after the supply of the NH₃ gas is stopped acts not only as apressure-increasing gas that increases the internal pressure of theprocess chamber 201 but also as a stirring gas (or a piston) that stirs(or diffuses) the NH₃ gas in the process chamber 201. By the aboveactions of the N₂ gas, the NH₃ gas confined in the process chamber 201is uniformly spread within the process chamber 201 after the supply ofthe NH₃ gas is stopped. As a result, it is possible to improve theuniformity of the film thickness and the film quality of the SiCN filmbetween the planes of the wafers 200 and within the plane of each of thewafers 200.

According to this modification, a used amount of the NH₃ gas and a filmforming cost can be reduced.

(Modification 2)

As illustrated in FIG. 6, in the step of supplying the NH₃ gas, the NH₃gas may be allowed to preliminarily flow through the process chamber 201while the exhaust system is opened, and the NH₃ gas may then be suppliedinto and confined in the process chamber 201 while the exhaust system issealed. When the NH₃ gas is preliminarily flowed, the valves 243 b, 243d, and 243 e are opened while the APC valve 244 is opened. The openingdegree of the APC valve 244 may be smaller than the opening degree ofthe APC valve 244 at the step of supplying the BTCSM gas. For example,the APC valve 244 is slightly opened such that a gas flow moving fromthe interior of the process chamber 201 toward the exhaust system isslightly formed. By controlling the opening degree of the APC valve 244in the above manner, it is possible to sufficiently increase theinternal pressure of the process chamber 201 when the NH₃ gaspreliminarily flows through the process chamber 201, which canefficiently activate the NH₃ gas supplied into the process chamber 201.Thereafter, the APC valve 244 is fully closed to cut off the gas flowmoving from the interior of the process chamber 201 toward the exhaustsystem, so as to confine the NH₃ gas in the process chamber 201.Processing procedures and processing conditions at the step of supplyingthe BTCSM gas in this modification may be the same as those of the filmforming sequence illustrated in FIG. 4.

In this modification, the same effects as those of the film formingsequence illustrated in FIG. 4 may be achieved.

According to this modification, a film quality of the SiCN film can beimproved, for the following reasons. When the confinement of the NH₃ gasin the process chamber 201 is started, there may be a case where a smallamount of the BTCSM gas remains in the process chamber 201, for example,on surfaces of members disposed in the process chamber 201. In thiscase, if the confinement of the NH₃ gas in the process chamber 201 isstarted, the BTCSM gas and the NH₃ gas react with each other. Thus, areaction byproduct such as ammonium chloride (NH₄Cl) or the like may begenerated in the process chamber 201. Particles including the reactionbyproduct may sometimes be generated in the process chamber 201. If suchparticles are confined in the process chamber 201 together with the NH₃gas, the particles may be introduced into the SiCN film, eventuallydeteriorating the film quality of the SiCN film. In this modification,before the confinement of the NH₃ gas into the process chamber 201 isstarted, the NH₃ gas is first allowed to preliminarily flow through theprocess chamber 201 while the exhaust system is opened, which canfacilitate removal of the reaction byproduct and the particles from theinterior of the process chamber 201. As a result, the film quality ofthe SiCN film can be improved.

(Modification 3)

Instead of the step of supplying the NH₃ gas, a step of supplying a gascontaining N and C, such as a TEA gas or the like, may be performed.Specifically, a cycle that non-simultaneously performs a step ofsupplying a BTCSM gas and a step of supplying a gas containing N and Csuch as a TEA gas or the like may be performed a predetermined number oftimes (e.g., n times).

At the step of supplying the TEA gas, the TEA gas is supplied to thewafer 200 in the process chamber 201 while the exhaust system is sealed,such that the TEA gas is confined in the process chamber 201. As such,the TEA gas is allowed to flow from the gas supply pipe 232 b. Openingand closing controls of the APC valve 244 and the valves 243 b, 243 d,and 243 e are executed in the same manner as those of the APC valve 244and the valves 243 b, 243 d, and 243 e at Step 2 of the film formingsequence illustrated in FIG. 4. A supply flow rate of the TEA gascontrolled by the MFC 241 b is set to fall within a range, for example,of 100 to 10,000 sccm. A time for supplying the TEA gas into the processchamber 201, that is, a gas supply time (i.e., irradiation time), is setto fall within a range, for example, of 1 to 200 seconds, specifically,1 to 120 seconds, more specifically, 1 to 60 seconds. Other processingconditions may be the same, for example, as those of Step 2 of the filmforming sequence illustrated in FIG. 4. Moreover, processing proceduresand processing conditions at the step of supplying the BTCSM gas in thismodification may be the same as those of the film forming sequenceillustrated in FIG. 4.

By supplying the TEA gas into the process chamber 201 while the exhaustsystem is sealed, an internal pressure of the process chamber 201 isallowed to reach a pressure which falls within a range, for example, of400 to 5,000 Pa, specifically, 500 to 4,000 Pa. In this operation, apartial pressure of the TEA gas in the process chamber 201 reaches apressure which falls within a range, for example, of 360 to 4,950 Pa. Bysetting the internal pressure of the process chamber 201 and the partialpressure of the TEA gas in the process chamber 201 to fall within theabove high pressure zones, the TEA gas supplied into the process chamber201 can be efficiently activated by using heat, under a non-plasmacondition, although an internal temperature of the process chamber 201is set to fall within a relatively low temperature zone, for example, of400 to 500 degrees C.

By supplying the thermally-activated TEA gas to the wafer 200 under theabove conditions, the first layer (i.e., the Si-containing layercontaining C and Cl) formed on the wafer 200 can react with the TEA gasto modify the first layer. In this operation, a N component and a Ccomponent contained in the TEA gas are added to the first layer, suchthat a layer containing C and N, that is, a SiCN layer, is formed on thewafer 200. As a result of introduction of the C component in the TEAgas, the layer formed as above becomes a layer having a larger amount ofa C component (i.e., a C-rich layer) than the second layer formed by thefilm forming sequence illustrated in FIG. 4. The supply of the thermallyactivated TEA gas under a non-plasma condition can have the abovereaction to occur softly, which in turn can facilitate formation of theSiCN layer. When the SiCN layer is formed, impurities such as Cl and thelike included in the first layer generate a gaseous substance containingat least Cl in the course of the modification reaction of the firstlayer by the TEA gas, and the gaseous substance is exhausted from theinterior of the process chamber 201. As such, the impurities such as Cland the like included in the first layer are separated from the firstlayer by being extracted or desorbed from the first layer. Thus, theSiCN layer becomes a layer having fewer impurities such as Cl and thelike than the first layer.

After the SiCN layer is formed, the valve 243 b is closed to stop thesupply of the TEA gas. By the same processing procedures as those ofStep 2 of the film forming sequence illustrated in FIG. 4, the TEA gas,which has not reacted or remains after contributing to the formation ofthe SiCN layer, or reaction byproduct, remaining in the process chamber201, is removed from the interior of the process chamber 201.

As the N- and C-containing gas, in addition to the TEA gas, it may bepossible to use, for example, an ethylamine-based gas such as adiethylamine ((C₂H₅)₂NH, abbreviation: DEA) gas, a monoethylamine(C₂H₅NH₂, abbreviation: MEA) gas or the like, a methylamine-based gassuch as a trimethylamine ((CH₃)₃N, abbreviation: TMA) gas, adimethylamine ((CH₃)₂NH, abbreviation: DMA) gas, a monomethylamine(CH₃NH₂, abbreviation: MMA) gas or the like, a propylamine-based gassuch as a tripropylamine ((C₃H₇)₃N, abbreviation: TPA) gas, adipropylamine ((C₃H₇)₂NH, abbreviation: DPA) gas, a monopropylamine(C₃H₇NH₂, abbreviation: MPA) gas or the like, an isopropylamine-basedgas such as a triisopropylamine ([(CH₃)₂CH]₃N, abbreviation: TIPA) gas,a diisopropylamine ([(CH₃)₂CH]₂NH, abbreviation: DIPA) gas, amonoisopropylamine ((CH₃)₂CHNH₂, abbreviation: MIPA) gas or the like, abutylamine-based gas such as a tributylamine (C₄H₉)₃N, abbreviation:TBA) gas, a dibutylamine ((C₄H₉)₂NH, abbreviation: DBA) gas, amonobutylamine (C₄H₉NH₂, abbreviation: MBA) gas or the like, and anisobutylamine-based gas such as a triisobutylamine ([(CH₃)₂CHCH₂]₃N,abbreviation: TIBA) gas, a diisobutylamine ([(CH₃)₂CHCH₂]₂NH,abbreviation: DIBA) gas, a monoisobutylamine ((CH₃)₂CHCH₂NH₂,abbreviation: MIBA) gas or the like. As such, at least one of the gasesdenoted as composition formulae, (C₂H₅)_(x)NH_(3-x), (CH₃)NH_(3-x),(C₃H₇)_(x)NH_(3-x), [(CH₃)₂CH]_(x)NH_(3-x), (C₄H₉)_(x)NH_(3-x) and[(CH₃)₂CHCH₂]_(x)NH_(3-x) (where x is an integer of 1 to 3) may be usedas the amine-based gas. In order to increase C concentration while anincrease of N concentration in the SiCN film is suppressed, a gas havinga molecule in which the number of C atoms is larger than the number of Natoms may be used as the amine-based gas. Specifically, a gas whichcontains at least one amine selected from a group consisting of TEA,DEA, MEA, TMA, DMA, TPA, DPA, MPA, TIPA, DIPA, MIPA, TBA, DBA, MBA,TIBA, DIBA, and MIBA may be used as the amine-based gas.

As the N- and C-containing gas, in addition to the amine-based gas, itmay be possible to use, for example, an organic hydrazine-based gas.Herein, the organic hydrazine-based gas refers to gaseous organichydrazine (or compound), for example, a gas which is obtained byvaporizing organic hydrazine in a liquid state under room temperatureand atmospheric pressure or a gas which contains a hydrazine group, suchas organic hydrazine or the like, in a gaseous state under roomtemperature and atmospheric pressure. The organic hydrazine-based gasmay be simply referred to as an organic hydrazine gas or an organichydrazine compound gas. The organic hydrazine-based gas is a Si-free gascomposed of three elements, C, N, and H, and is a gas which does notcontain Si and metal. As the organic hydrazine-based gas, it may bepossible to use, for example, a methylhydrazine-based gas such as amonomethylhydrazine ((CH₃)HN₂H₂, abbreviation: MMH) gas, adimethylhydrazine ((CH₃)₂N₂H₂, abbreviation: DMH) gas, atrimethylhydrazine ((CH₃)₂N₂ (CH₃)H, abbreviation; TMH) gas or the like,and an ethylhydrazine-based gas such as an ethylhydrazine ((C₂H₅)HN₂H₂,abbreviation: EH) gas or the like. In order to increase the Cconcentration while an increase of the N concentration in the SiCN filmis suppressed, a gas having a molecule in which the number of C atoms islarger than the number of N atoms may be used as the organichydrazine-based gas.

As the amine-based gas or the organic hydrazine-based gas, it may bepossible to use a gas having a plurality of C-containing ligands in onemolecule, that is, a gas having a plurality of hydrocarbon groups suchas alkyl groups or the like in one molecule. More specifically, as theamine-based gas or the organic hydrazine-based gas, it may be possibleto use a gas having three or two C-containing ligands (e.g., hydrocarbongroups such as alkyl groups or the like), i.e., organic ligands, in onemolecule.

By performing one or more times (e.g., a predetermined number of times)a cycle that non-simultaneously performs the above respective steps, itis possible to form a SiCN film having a predetermined composition and apredetermined thickness on the wafer 200. As described above withrespect to the film forming sequence illustrated in FIG. 4, a thicknessof the SiCN layer formed per one cycle may be set to be smaller than adesired film thickness, and the above cycle may be repeated multipletimes until the desired film thickness is obtained.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 may be achieved. In addition, byperforming the step of supplying the TEA gas which acts as a C source,in other words, by performing film formation by using two kinds ofcarbon sources (i.e., double carbon sources) in one cycle, the SiCN filmformed on the wafer 200 becomes a film having a larger amount of a Ccomponent (i.e., C-rich film) than the SiCN film that is formed in thefilm forming sequence illustrated in FIG. 4. As such, a window forcontrolling a composition ratio of the SiCN film may be expanded.

(Modification 4)

As illustrated in FIG. 7, a step of supplying an oxygen-containing gassuch as an O₂ gas or the like may be additionally performed.Specifically, a cycle that non-simultaneously performs a step ofsupplying a BTCSM gas, a step of supplying a NH₃ gas, and a step ofsupplying an oxygen-containing gas such as an O₂ gas or the like may beperformed a predetermined number of times (e.g., n times). Processingprocedures and processing conditions at the step of supplying the BTCSMgas and the step of supplying the NH₃ gas in this modification may bethe same as those of the film forming sequence illustrated in FIG. 4.

At the step of supplying the O₂ gas, the O₂ gas is supplied to thewafers 200 in the process chamber 201 while the exhaust system issealed, such that the O₂ gas is confined in the process chamber 201. Inthis operation, the O₂ gas is allowed to flow from the gas supply pipe232 b. Opening and closing controls of the APC valve 244 and the valves243 b, 243 d, and 243 e are executed in the same manner as those of theAPC valve 244 and the valves 243 b, 243 d, and 243 e at Step 2 of thefilm forming sequence illustrated in FIG. 4. A supply flow rate of theO₂ gas controlled by the MFC 241 b is set to fall within a range, forexample, of 100 to 10,000 sccm. A time for supplying the O₂ gas into theprocess chamber 201, that is, a gas supply time (i.e., irradiationtime), is set to fall within a range, for example, of 1 to 120 seconds,specifically, 1 to 60 seconds. Other processing conditions may be thesame, for example, as those of step 2 of the film forming sequenceillustrated in FIG. 4.

By supplying the O₂ gas into the process chamber 201 while the exhaustsystem is sealed, an internal pressure of the process chamber 201 isallowed to reach a pressure which falls within a range, for example, of400 to 5,000 Pa, specifically, 500 to 4,000 Pa. In this operation, apartial pressure of the O₂ gas in the process chamber 201 becomes apressure which falls within a range, for example, of 360 to 4,950 Pa. Bysetting the internal pressure of the process chamber 201 and the partialpressure of the O₂ gas in the process chamber 201 to fall within theabove high pressure zones, the O₂ gas supplied into the process chamber201 may be efficiently activated by using heat, under a non-plasmacondition, and oxidizing power of the O₂ gas may be increased, althoughan internal temperature of the process chamber 201 is set to fall withina relatively low temperature zone, for example, of 400 to 500 degrees C.

By supplying the thermally-activated O₂ gas to the wafers 200 under theabove conditions, at least a portion of the second layer (i.e., SiCNlayer) formed on the wafer 200 is oxidized (i.e., modified). As a resultof the modification of the SiCN layer, a layer containing O, C, and N,that is, a silicon oxycarbonitride layer (SiOCN layer), is formed on thewafer 200. When the SiOCN layer is formed, impurities such as Cl and thelike included in the SiCN layer generate a gaseous substance containingat least Cl in the course of the modification reaction of the SiCN layerby the O₂ gas, and the gaseous substance is exhausted from the interiorof the process chamber 201. As such, the impurities such as Cl and thelike included in the SiCN layer are separated from the SiCN layer bybeing extracted or desorbed from the SiCN layer. Thus, the SiOCN layerbecomes a layer having fewer impurities such as Cl and the like than theSiCN layer. The supply of the thermally activated O₂ gas under anon-plasma condition can have the above reaction to occur softly, whichfacilitates the formation the SiOCN layer.

After the SiOCN layer is formed, the valve 243 b is closed to stop thesupply of the O₂ gas. By the same processing procedures as those of Step2 of the film forming sequence illustrated in FIG. 4, the O₂ gas, whichhas not reacted or remained after contributing to the formation of theSiOCN layer, or reaction byproduct, remaining in the process chamber201, is removed from the interior of the process chamber 201.

As the oxygen-containing gas, in addition to the O₂ gas, it may bepossible to use, for example, a nitrous oxide (N₂O) gas, a nitricmonoxide (NO) gas, a nitrogen dioxide (NO₂) gas, an ozone (O₃) gas, ahydrogen (H₂)+O₂ gas, a H₂+O₃ gas, a water vapor (H₂O), a carbonmonoxide (CO) gas, or a carbon dioxide (CO₂) gas.

By performing one or more times (e.g., a predetermined number of times)a cycle that non-simultaneously performs the respective steps asdescribed above, it is possible to form a silicon oxycarbonitride film(SiOCN film) having a predetermined composition and a predeterminedthickness, as a film containing Si, 0, C, and N, on the wafer 200. Asdescribed above with respect to the film forming sequence illustrated inFIG. 4, a thickness of the SiOCN layer formed per one cycle may be setto be smaller than a desired film thickness, and the above cycle may berepeated multiple times until the desired film thickness is obtained.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 may be achieved. In addition, thesupply of the O₂ gas makes it possible to further desorb the impuritiessuch as Cl and the like from the SiCN layer. Accordingly, impurityconcentration in the SiOCN film can be reduced, and thus, HF resistanceof the film can be increased.

(Modification 5)

Instead of the step of supplying the NH₃ gas, a step of supplying a TEAgas may be performed. Additionally, a step of supplying an O₂ gas may beperformed. Specifically, a cycle that non-simultaneously performs a stepof supplying a BTCSM gas, a step of supplying a TEA gas, and a step ofsupplying an O₂ gas may be performed a predetermined number of times(e.g., n times). Processing procedures and processing conditions in therespective steps of this modification may be the same as those of thefilm forming sequence illustrated in FIG. 4 or those of Modifications 3and 4 as described above.

A SiCN layer is formed on the wafer 200 by performing the step ofsupplying the BTCSM gas and the step of supplying the TEA gas.Thereafter, at least a portion of the SiCN layer formed on the wafer 200is oxidized (i.e., modified) by performing the step of supplying the O₂gas. In this operation, if oxidizing power is increased, for example, byincreasing a target internal pressure of the process chamber 201, mostof N atoms contained in the SiCN layer may be desorbed such that the Natoms are left at an impurity level. Also, the N atoms contained in theSiCN layer may be extinguished substantially. As such, the SiCN layer ismodified into a SiOCN layer or a silicon oxycarbide layer (SiOC layer).The supply of the thermally activated O₂ gas under a non-plasmacondition can have the above reaction to occur softly, which in turn canfacilitate the formation the SiOCN layer or the SiOC layer. According tothis modification, a SiOCN film or a silicon oxycarbide film (SiOC film)is formed on the wafer 200.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 and those of modifications 3 and4 may be achieved. In addition, the supply of the O₂ gas makes itpossible to further desorb the impurities such as Cl and the like fromthe SiCN layer. Accordingly, impurity concentration in the SiOCN film orthe SiOC film may be reduced, and HF resistance of the film may beincreased.

(Modification 6)

Instead of the step of supplying the NH₃ gas, it may be possible toperform a step of supplying an O₂ gas. Specifically, a cycle thatnon-simultaneously performs a step of supplying a BTCSM gas and a stepof supplying an O₂ gas may be performed a predetermined number of times(e.g., n times). Processing procedures and processing conditions at therespective steps in this modification may be the same as those of thefilm forming sequence illustrated in FIG. 4 or those of Modification 4as described above.

A first layer (i.e., a Si-containing layer containing C and Cl) isformed on the wafer 200 by performing the step of supplying the BTCSMgas. Thereafter, at least a portion of the first layer formed on thewafer 200 is oxidized (i.e., modified) by performing the step ofsupplying the O₂ gas. As a result of the modification of the firstlayer, a layer containing Si, O, and C, that is, a silicon oxycarbidelayer (SiOC layer), is formed on the wafer 200. According to thismodification, a silicon oxycarbide film (SiOC film) having apredetermined composition and a predetermined film thickness, as a filmcontaining Si, O, and C, is formed on the wafer 200.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 may be achieved. In addition, thesupply of the O₂ gas makes it possible to desorb the impurities such asCl and the like from the first layer. Accordingly, impurityconcentration in the finally-formed SiOC film may be reduced and HFresistance of the film may be increased.

(Modification 7)

A step of supplying a borane-based gas such as a BCl₃ gas or the likemay be performed between the step of supplying the BTCSM gas and thestep of supplying the NH₃ gas. Specifically, a cycle thatnon-simultaneously performs a step of supplying a BTCSM gas, a step ofsupplying a borane-based gas such as a BCl₃ gas or the like, and a stepof supplying a NH₃ gas may be performed a predetermined number of times(e.g., n times). Processing procedures and processing conditions at thestep of supplying the BTCSM gas and the step of supplying the NH₃ gas inthis modification may be the same as those of the film forming sequenceillustrated in FIG. 4.

At the step of supplying the BCl₃ gas, the BCl₃ gas is supplied to thewafers 200 in the wafer 200 while the exhaust system is sealed, suchthat the BCl₃ gas is confined in the process chamber 201. In thisoperation, the BCl₃ gas is allowed to flow from the gas supply pipe 232b. Opening and closing controls of the APC valve 244 and the valves 243b, 243 d, and 243 e are executed in the same manner as those of the APCvalve 244 and the valves 243 b, 243 d, and 243 e at Step 2 of the filmforming sequence illustrated in FIG. 4. A supply flow rate of the BCl₃gas controlled by the MFC 241 b is set to fall within a range, forexample, of 100 to 10,000 sccm. A time for supplying the BCl₃ gas intothe process chamber 201, that is, a gas supply time (i.e., irradiationtime), is set to fall within a range, for example, of 1 to 120 seconds,specifically, 1 to 60 seconds. Other processing conditions may be thesame, for example, as the processing conditions of step 2 of the filmforming sequence illustrated in FIG. 4.

By supplying the BCl₃ gas into the process chamber 201 while the exhaustsystem is sealed, an internal pressure of the process chamber 201 isallowed to reach a pressure which falls within a range, for example, of400 to 5,000 Pa, specifically, 500 to 4,000 Pa. In this operation, apartial pressure of the BCl₃ gas in the process chamber 201 becomes apressure which falls within a range, for example, of 360 to 4,950 Pa. Bysetting the internal pressure of the process chamber 201 and the partialpressure of the BCl₃ gas in the process chamber 201 to fall within theabove high pressure zones, the BCl₃ gas supplied into the processchamber 201 may be efficiently activated by using heat, under anon-plasma condition, even if an internal temperature of the processchamber 201 is set to fall within a relatively low temperature zone of,for example, 400 to 500 degrees C.

By supplying the BCl₃ gas to the wafer 200 under the above conditions, aB-containing layer having a thickness of less than one atomic layer,that is, a discontinuous B-containing layer, is formed on the surface ofthe first layer (i.e., the Si-containing layer containing C and Cl)formed on the wafer 200. The B-containing layer may be a B layer, achemical adsorption layer of the BCl₃ gas, or both of them. As a resultof the formation of the B-containing layer on the surface of the firstlayer, a layer containing Si, B, and C is formed on the wafer 200. Sincethe BCl₃ gas is a non-borazine-based boron-containing gas, the layercontaining Si, B, and C becomes a borazine-ring-skeleton-free layer. Thesupply of the thermally activated BCl₃ gas have the above reaction tooccur softly under a non-plasma condition, which in turn can facilitatethe formation of the layer containing Si, B, and C.

As the borazine-ring-skeleton-free boron-containing gas, in addition tothe BCl₃ gas, it may be possible to use a halogenated boron-based gas(haloborane-based gas) other than the BCl₃ gas, e.g., achloroborane-based gas other than the BCl₃ gas, a fluoroborane-based gassuch as a trifluoroborane (BF₃) gas or the like, and a bromoborane-basedgas such as a tribromoborane (BBr₃) gas or the like. Also, aborane-based gas such as a B₂H₆ gas or the like may be used. Further, inaddition to the inorganic borane-based gas, an organic borane-based gasmay be used.

After the layer containing Si, B, and C is formed, the valve 243 b isclosed to stop the supply of the BCl₃ gas. By the same processingprocedures as those of Step 2 of the film forming sequence illustratedin FIG. 4, the BCl₃ gas which has not reacted or remains aftercontributing to the formation of the layer containing Si, B, and C, orthe reaction byproduct, remaining in the process chamber 201, is removedfrom the interior of the process chamber 201.

Thereafter, the step of supplying the NH₃ gas to the wafer 200 isperformed. Thus, the layer containing Si, B, and C is modified into alayer containing Si, B, C, and N, that is, a silicon borocarbonitridelayer (SiBCN layer).

By performing one or more times (e.g., a predetermined number of times)the cycle that non-simultaneously performs the respective steps asdescribed above, it is possible to form a silicon borocarbonitride film(SiBCN film) having a predetermined composition and a predeterminedthickness, as a film containing Si, B, C, and N, on the wafer 200. Asdescribed above with respect to the film forming sequence illustrated inFIG. 4, a thickness of the SiBCN layer formed per one cycle may be setto be smaller than a desired film thickness, and the above cycle isrepeated multiple times until the desired film thickness is obtained.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 and those of the respectivemodifications as described above may be achieved. In addition, additionof B to the film formed on the wafer 200 may increase, for example, HFresistance of the film.

(Modification 8)

A step of supplying a TEA gas may be performed instead of the step ofsupplying the NH₃ gas, and a step of supplying a BCl₃ gas may beperformed between the step of supplying the BTCSM gas and the step ofsupplying the TEA gas. Specifically, a cycle that non-simultaneouslyperforms a step of supplying a BTCSM gas, a step of supplying a BCl₃gas, and a step of supplying a TEA gas may be performed a predeterminednumber of times (e.g., n times). According to this modification, a SiBCNfilm is formed on the wafer 200. Processing procedures and processingconditions at the respective steps in this modification may be the sameas those of the film forming sequence illustrated in FIG. 4 and those ofModifications 3 and 7.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 and those of Modification 7 maybe achieved. In addition, by performing the step of supplying the TEAgas, the SiBCN film formed on the wafer 200 becomes a film having alarger amount of a C component (i.e., C-rich film) than the SiBCN filmformed in Modification 7. As such, a window for controlling acomposition ratio of the SiBCN film may be expanded.

(Modification 9)

A step of supplying a borazine-based gas such as a TMB gas or the likemay be performed instead of the step of supplying the NH₃ gas.Specifically, a cycle that non-simultaneously performs a step ofsupplying a BTCSM gas and a step of supplying a borazine-based gas suchas a TMB gas or the like may be performed a predetermined number oftimes (e.g., n times). Processing procedures and processing conditionsat the step of supplying the BTCSM gas in this modification may be thesame as those of the film forming sequence illustrated in FIG. 4.

At the step of supplying the TMB gas, the TMB gas is supplied to thewafers 200 in the wafer 200 while the exhaust system is sealed, suchthat the TMB gas is confined in the process chamber 201. In thisoperation, the TMB gas is allowed to flow from the gas supply pipe 232b. Opening and closing controls of the APC valve 244 and the valves 243b, 243 d, and 243 e are executed in the same manner as those of the APCvalve 244 and the valves 243 b, 243 d, and 243 e at Step 2 of the filmforming sequence illustrated in FIG. 4. A supply flow rate of the TMBgas controlled by the MFC 241 b is set to fall within a range, forexample, of 1 to 1,000 sccm. A time for supplying the TMB gas into theprocess chamber 201, that is, a gas supply time (i.e., irradiationtime), is set to fall within a range, for example, of 1 to 120 seconds,specifically, 1 to 60 seconds. Other processing conditions may be thesame, for example, as the processing conditions of Step 2 of the filmforming sequence illustrated in FIG. 4.

By supplying the TMB gas into the process chamber 201 while the exhaustsystem is sealed, an internal pressure of the process chamber 201 isallowed to reach a pressure which falls within a range, for example, of400 to 5,000 Pa, specifically, 500 to 4,000 Pa. In this operation, apartial pressure of the TMB gas in the process chamber 201 becomes apressure which falls within a range, for example, of 360 to 4,950 Pa. Bysetting the internal pressure of the process chamber 201 and the partialpressure of the TMB gas in the process chamber 201 to fall within theabove high pressure zones, the TMB gas supplied into the process chamber201 may be efficiently activated by using heat, under a non-plasmacondition, even if an internal temperature of the process chamber 201 isset to fall within a relatively low temperature zone, for example, of400 to 500 degrees C.

As the TMB gas is supplied to the wafer 200 under the above conditions,the first layer (i.e., Si-containing layer containing C and Cl) reactswith the TMB gas. Specifically, Cl (i.e., chloro group) contained in thefirst layer reacts with a ligand (i.e., methyl group) contained in theTMB. Thus, the Cl of the first layer reacting with the ligand of the TMBmay be separated (or extracted) from the first layer. The ligand of theTMB reacting with the Cl of the first layer may be separated from theTMB. Then, N that constitutes a borazine ring of the TMB, from which theligand is separated, can be bonded to Si of the first layer.Specifically, among B and N constituting the borazine ring of the TMB,the N, which has been caused to have a dangling bond due to theseparation of the methyl ligand, may be bonded to the Si contained inthe first layer, which has been caused to have a dangling bond, ororiginally provided with a dangling bond, so as to form a Si—N bond. Inthis operation, a borazine ring skeleton constituting the borazine ringof the TMB is maintained without being broken.

By supplying the TMB gas under the above conditions, the first layer canproperly react with the TMB while the borazine ring skeleton of the TMBis maintained without being broken, which may allow a series ofreactions as described above. Most important factors (or conditions) forallowing the series of reactions while the borazine ring skeleton of theTMB is maintained are considered to be a temperature of the wafers 200and an internal temperature of the process chamber 201, particularly,the temperature of the wafers 200. Appropriately controlling thosefactors allows appropriate reactions to occur.

Through the series of reactions, the borazine ring is newly introducedinto the first layer, and the first layer is changed (or modified) intoa layer including a borazine ring skeleton and containing Si, B, C, andN, that is, a silicon borocarbonitride layer (SiBCN layer) having aborazine ring skeleton. The SiBCN layer including a borazine ringskeleton becomes a layer having a thickness, for example, of less thanone atomic layer to several atomic layers. The SiBCN layer including aborazine ring skeleton may also be referred to as a layer containing Si,C, and a borazine ring skeleton.

As the borazine ring is newly introduced into the first layer, a Bcomponent and a N component constituting the borazine ring areintroduced into the first layer. In this operation, a C componentcontained in the ligand of the TMB is also introduced into the firstlayer. As such, if the borazine ring is introduced into the first layerby causing the first layer to react with the TMB, the B component, the Ccomponent, and the N component can be added into the first layer.

While the SiBCN layer including a borazine ring skeleton is formed, Clwhich was contained in the first layer or H which was contained in theTMB gas generates a gaseous substance containing at least Cl or H in thecourse of the modification reaction of the first layer by using the TMBgas. Such gaseous substance is exhausted from the interior of theprocess chamber 201. As such, impurities such as Cl and the likeincluded in the first layer are separated from the first layer by beingextracted or desorbed from the first layer. Thus, the SiBCN layerincluding a borazine ring skeleton becomes a layer having fewerimpurities such as Cl and the like than the first layer.

During the formation of the SiBCN layer including a borazine ringskeleton, if the borazine ring skeleton that constitutes the borazinering of the TMB is maintained without being broken, it is possible tomaintain a central space of the borazine ring and thus form a porousSiBCN layer.

After the SiBCN layer including a borazine ring skeleton is formed, thevalve 243 b is closed to stop the supply of the TMB gas. Then, the TMBgas which has not reacted or remains after contributing to the formationof the SiBCN layer including a borazine ring skeleton, or reactionbyproduct, remaining in the process chamber 201, is removed from theinterior of the process chamber 201 by the same processing procedures asused at Step 1.

As the borazine-ring-skeleton-containing gas, in addition to the TMBgas, it may be possible to use, for example, a TEB gas, a TPB gas, aTIPB gas, a TBB gas or a TIBB gas.

By performing one or more times (e.g., a predetermined number of times)the cycle that non-simultaneously performs the respective steps asdescribed above, it is possible to form a SiBCN film having apredetermined composition and a predetermined thickness and including aborazine ring skeleton on the wafer 200. As described above with respectto the film forming sequence illustrated in FIG. 4, a thickness of theSiBCN layer formed per one cycle may be set to be smaller than a desiredfilm thickness, and the above cycle may be repeated multiple times untilthe desired film thickness is obtained.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 and those of Modifications 7 and8 may be achieved. In addition, the film formed on the wafer 200includes a film including a borazine ring skeleton, that is, a porousfilm having a low atomic density. Therefore, a dielectric constant ofthe film may be lower than that of the SiBCN film, for example, formedin Modifications 7 and 8. Moreover, the film formed on the wafer 200includes a film including a borazine ring skeleton, that is, a filmcontaining B as a component of the borazine ring skeleton thatconstitutes the film, which may improve oxidation resistance of thefilm.

(Modification 10)

A step of supplying a precursor gas containing Si and Cl and having aSi—Si bond, such as a HCDS gas or the like, may be performed instead ofthe step of supplying the BTCSM gas. Specifically, a cycle thatnon-simultaneously performs a step of supplying a precursor gascontaining Si and Cl and having a Si—Si bond, such as a HCDS gas or thelike, and a step of supplying a NH₃ gas may be performed a predeterminednumber of times (e.g., n times). Processing procedures and processingconditions at the step of supplying the NH₃ gas in this modification maybe the same as those of the film forming sequence illustrated in FIG. 4.

At the step of supplying the HCDS gas, the HCDS gas is allowed to flowfrom the gas supply pipe 232 a. Opening and closing controls of the APCvalve 244 and the valves 243 a, 243 d, and 243 e are executed in thesame manner as those of the APC valve 244 and the valves 243 a, 243 d,and 243 e at Step 1 of the film forming sequence illustrated in FIG. 4.A supply flow rate of the HCDS gas controlled by the MFC 241 a is set tofall within a range, for example, of 1 to 2,000 sccm, specifically, 10to 1,000 sccm. A temperature of the heater 207 is set such that atemperature of the wafers 200 reaches a temperature which falls within arange, for example, of 250 to 700 degrees C., specifically, 300 to 650degrees C., more specifically, 350 to 600 degrees C. Other processingconditions may be the same, for example, as those of Step 1 of the filmforming sequence illustrated in FIG. 4.

If a temperature of the wafers 200 is less than 250 degrees C., it ishard for HCDS to be chemically adsorbed onto the wafers 200, and thus, apractical film forming rate may not be obtained. This problem can besolved by increasing the temperature of the wafers 200 to be 250 degreesC. or higher. By setting the temperature of the wafers 200 to be 300degrees C. or higher, specifically, 350 degrees C. or higher, the HCDSgas can be sufficiently adsorbed onto the wafer 200, which may lead toobtaining a considerably sufficient film forming rate.

If the temperature of the wafers 200 exceeds 700 degrees C., a CVDreaction becomes intensive (in other words, a gas phase reaction becomesdominant). Thus, film thickness uniformity may be hard to control andoften deteriorate. By setting the temperature of the wafers 200 to be700 degrees C. or lower, such deterioration of the film thicknessuniformity can be suppressed and the film thickness uniformity can becontrolled. In particular, a surface reaction becomes dominant bysetting the temperature of the wafers 200 to be 650 degrees C. or lower,specifically, 600 degrees C. or lower, and thus, it becomes possible tosecure the film thickness uniformity and control the film thicknessuniformity.

Accordingly, the temperature of the wafers 200 may be set to fall withina range of 250 to 700 degrees C., specifically, 300 to 650 degrees C.,more specifically, 350 to 600 degrees C.

By supplying the HCDS gas to the wafer 200 under the above conditions, afirst layer, that is, a Si-containing layer containing Cl and having athickness, for example, of less than one atomic layer to several atomiclayers, is formed on the wafer 200 (or a base film of its surface). TheSi-containing layer containing Cl may be a Si layer containing Cl, anadsorption layer of the HCDS gas, or both.

Herein, the phrase “a Si layer containing Cl” is a generic name whichencompasses a continuous layer and a discontinuous layer that are formedof Si and contain Cl, and a Si thin film containing Cl that is formed bylaminating the above layers. The continuous layer that is formed of Siand contains Cl may be referred to as a Si thin film containing Cl. Inaddition, Si constituting the Si layer containing Cl includes Si whosebond to Cl is completely broken, in addition to Si whose bond to Cl isnot completely broken.

An adsorption layer of the HCDS gas includes a continuous adsorptionlayer in which gas molecules of the HCDS gas are continuous, and adiscontinuous adsorption layer in which gas molecules of the HCDS gasare discontinuous. In other words, the adsorption layer of the HCDS gasmay include an adsorption layer formed of HCDS molecules and having athickness of one molecular layer or less than one molecular layer. TheHCDS molecules that constitute the adsorption layer of the HCDS gasinclude a molecule in which a bond between Si and Cl is partiallybroken. As such, the adsorption layer of the HCDS gas may include aphysical adsorption layer of the HCDS gas, a chemical adsorption layerof the HCDS gas, or both.

Herein, a layer having a thickness of less than one atomic layer refersto a discontinuously formed atomic layer. A layer having a thickness ofone atomic layer refers to a continuously formed atomic layer. A layerhaving a thickness of less than one molecular layer means a molecularlayer that is discontinuously formed. The layer having a thickness ofone molecular layer refers to a continuously formed molecular layer. ASi-containing layer containing Cl may include both of a Si layercontaining Cl and an adsorption layer of a HCDS gas. As described above,the Si-containing layer containing Cl is described with the terms suchas “one atomic layer,” “several atomic layers,” and the like.

Under a condition in which the HCDS gas is autolyzed (or pyrolyzed),that is, a condition in which a pyrolysis reaction of the HCDS gasoccurs, Si is deposited on the wafer 200 to form a Si layer containingCl. Under a condition in which the HCDS gas is not autolyzed (orpyrolyzed), that is, a condition in which a pyrolysis reaction of theHCDS gas does not occur, the HCDS gas is adsorbed onto the wafer 200 toform an adsorption layer of the HCDS gas. From the viewpoint ofincreasing a film forming rate, it may be more advantageous to form theSi layer containing Cl on the wafer 200 than to form the adsorptionlayer of the HCDS gas on the wafer 200.

If a thickness of the first layer formed on the wafer 200 exceedsseveral atomic layers, an effect of a modification reaction at the stepof supplying the NH₃ gas is not to be applied to the entire first layer.On the other hand, a minimum value of the thickness of the first layerto be formed on the wafer 200 is less than one atomic layer.Accordingly, the thickness of the first layer may be set to fall withina range of less than one atomic layer to several atomic layers. Inaddition, when the thickness of the first layer is set to be one atomiclayer or less (i.e., one atomic layer or less than one atomic layer),the effect of the modification reaction at the step of supplying the NH₃gas can be relatively increased. This makes it possible to shorten atime required for the modification reaction at the step of supplying theNH₃ gas. It is also possible to shorten a time required for forming thefirst layer at the step of supplying the HCDS gas. As such, a processingtime per cycle can be shortened, and a total processing time can also beshortened. Accordingly, a film forming rate can be increased. Inaddition, if the thickness of the first layer is set to be one atomiclayer or less, it is possible to better control film thicknessuniformity.

As the precursor gas, in addition to the HCDS gas, it may be possible touse, for example, an inorganic precursor gas such as a tetrachlorosilanegas, that is, a silicon tetrachloride (SiCl₄, abbreviation: STC) gas, atrichlorosilane (SiHCl₃, abbreviation: TCS) gas, a dichlorosilane(SiH₂Cl₂, abbreviation: DCS) gas, a monochlorosilane (SiH₃Cl,abbreviation: MCS) gas, or the like. As the inert gas, in addition tothe N₂ gas, it may be possible to use, for example, a rare gas such asan Ar gas, a He gas, a Ne gas, a Xe gas, or the like.

After the first layer is formed, by the same processing procedures asthose of Step 1 of the film forming sequence illustrated in FIG. 4, theHCDS gas which has not reacted or remains after contributing to theformation of the first layer, remaining in the process chamber 201, isexhausted through the exhaust system and is then removed from theinterior of the process chamber 201.

Thereafter, at least a portion of the first layer (i.e., theSi-containing layer containing Cl) formed on the wafer 200 is nitrided(i.e., modified) by performing the step of supplying the NH₃ gas. As aresult of the modification of the first layer, a layer containing Si andN, that is, a silicon nitride layer (SiN layer), is formed on the wafer200. The supply of the thermally activated NH₃ gas under a non-plasmacondition can have the above reaction to occur softly, which in turn canfacilitate the formation of the SiN layer. When the SiN layer is formed,impurities such as Cl and the like included in the first layer areseparated from the first layer by being extracted or desorbed from thefirst layer. This aspect is the same as that of the film formingsequence illustrated in FIG. 4. Thus, the SiN layer becomes a layerhaving fewer impurities such as Cl and the like than the first layer. Atthe step of supplying the NH₃ gas, the temperature of the wafers 200 isset to be equal to the temperature of the wafers 200 used at the step ofsupplying the HCDS gas. Other processing conditions may be the same asthe processing conditions of Step 2 of the film forming sequenceillustrated in FIG. 4.

By performing one or more times (e.g., a predetermined number of times)the cycle that non-simultaneously performs the respective steps asdescribed above, it is possible to form a SiN film having apredetermined composition and a predetermined thickness, as a filmcontaining Si and N, on the wafer 200. As described above with respectto the film forming sequence illustrated in FIG. 4, a thickness of theSiN layer formed per one cycle may be set to be smaller than a desiredfilm thickness, and the above cycle may be repeated multiple times untilthe desired film thickness is obtained.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 may be achieved.

(Modification 11)

A cycle that non-simultaneously performs a step of supplying a HCDS gas,a step of supplying a NH₃ gas, and a step of supplying an O₂ gas may beperformed a predetermined number of times (e.g., n times). According tothis modification, a SiON film is formed on the wafer 200. Processingprocedures and processing conditions at the respective steps in thismodification may be the same as those of Modification 10, the filmforming sequence illustrated in FIG. 4, and Modification 4. According tothis modification, the same effects as those of the film formingsequence illustrated in FIG. 4 and those of Modification 4 may beachieved.

(Modification 12)

A cycle that non-simultaneously performs a step of supplying a HCDS gas,a step of supplying a C₃H₆ gas, and a step of supplying a NH₃ gas may beperformed a predetermined number of times (e.g., n times). Processingprocedures and processing conditions at the step of supplying the HCDSgas and the step of supplying the NH₃ gas in this modification may bethe same as those of Modification 10 and those of the film formingsequence illustrated in FIG. 4.

At the step of supplying the C₃H₆ gas, the C₃H₆ gas is supplied to thewafers 200 in the wafer 200 while the exhaust system is sealed, suchthat the C₃H₆ gas is confined in the process chamber 201. In thisoperation, the C₃H₆ gas is allowed to flow from the gas supply pipe 232c. Opening and closing controls of the APC valve 244 and the valves 243c, 243 d, and 243 e are executed in the same manner as those of the APCvalve 244 and the valves 243 b, 243 d, and 243 e at Step 2 of the filmforming sequence illustrated in FIG. 4. A supply flow rate of the C₃H₆gas controlled by the MFC 241 c is set to fall within a range, forexample, of 100 to 10,000 sccm. A time for supplying the C₃H₆ gas intothe process chamber 201, that is, a gas supply time (i.e., irradiationtime), is set to fall within a range, for example, of 1 to 200 seconds,specifically, 1 to 120 seconds, more specifically, 1 to 60 seconds. Atemperature of the wafers 200 may be set equal to the temperature of thewafers 200 used at the step of supplying the HCDS gas. Other processingconditions may be the same, for example, as those of Step 2 of the filmforming sequence illustrated in FIG. 4.

By supplying the C₃H₆ gas into the process chamber 201 while the exhaustsystem is sealed, an internal pressure of the process chamber 201 isallowed to reach a pressure which falls within a range, for example, of400 to 5,000 Pa, specifically, 500 to 4,000 Pa. In this operation, apartial pressure of the C₃H₆ gas in the process chamber 201 becomes apressure which falls within a range, for example, of 360 to 4,950 Pa. Bysetting the internal pressure of the process chamber 201 and the partialpressure of the C₃H₆ gas in the process chamber 201 to fall within theabove high pressure zones, the C₃H₆ gas supplied into the processchamber 201 may be efficiently activated by using heat, under anon-plasma condition, even if an internal temperature of the processchamber 201 at Step 2 is set to fall within a relatively low temperaturezone, for example, of 400 to 500 degrees C.

By performing the step of supplying the C₃H₆ gas to the wafer 200 underthe above conditions, a C-containing layer having a thickness of lessthan one atomic layer, that is, a discontinuous C-containing layer, isformed on a surface of the first layer (i.e., Si-containing layercontaining Cl) formed on the wafer 200. The C-containing layer may be aC layer, a chemical adsorption layer of the C₃H₆ gas, or both.

After the C-containing layer is formed on the surface of the firstlayer, the valve 243 c is closed to stop the supply of the C₃H₆ gas. Bythe same processing procedures as those of Step 2 of the film formingsequence illustrated in FIG. 4, the C₃H₆ gas which has not reacted orremains after contributing to the formation of the C-containing layer,or reaction byproduct, remaining in the process chamber 201, is removedfrom the interior of the process chamber 201.

As the carbon-containing gas, in addition to the C₃H₆ gas, it may bepossible to use, for example, a hydrocarbon-based gas such as anacetylene (C₂H₂) gas, an ethylene (C₂H₄) gas or the like.

Thereafter, by performing the step of supplying the NH₃ gas to the wafer200, the first layer on which the C-containing layer is formed ismodified into a SiCN layer. In this operation, in order to reliablyperform a reaction of the NH₃ gas with the first layer on which theC-containing layer is formed, that is, formation of the SiCN layer, thestep of supplying the C₃H₆ gas may be finished before a reaction ofadsorption of C₃H₆ gas molecules onto a surface of the first layer issaturated, that is, before the C-containing layer such as the adsorptionlayer (i.e., chemical adsorption layer) of the C₃H₆ gas or the likeformed on the surface of the first layer becomes a continuous layer(i.e., while the C-containing layer is maintained as a discontinuouslayer).

By performing one or more times (e.g., a predetermined number of times)the cycle that non-simultaneously performs the three steps as describedabove, it is possible to form a SiCN film on the wafer 200. As describedabove with in respect to the film forming sequence illustrated in FIG.4, a thickness of the SiCN layer formed per one cycle may be set to besmaller than a desired film thickness and the above cycle may berepeated multiple times until the desired film thickness is obtained.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 may be achieved. Furthermore,according to this modification, the SiCN film is formed, an N-free gassuch as a C₃H₆ or the like, that is, a hydrocarbon-based gas which doesnot act as an N source, is used as the carbon-containing gas. Thus, a Ncomponent derived from the carbon-containing gas is prevented from beingadded to the SiCN film, which can increase C concentration in thefinally formed SiCN film while an increase of the N concentration in thefinally-formed SiCN film is suppressed. As such, a composition ratio ofthe SiCN film can be better controlled. Moreover, according to thismodification, the carbon-containing gas is confined within the processchamber 201. Therefore, as compared with the case where thecarbon-containing gas is not confined, the C concentration in the SiCNlayer can be increased significantly.

(Modification 13)

A cycle that non-simultaneously performs a step of supplying a HCDS gasand a step of supplying a TEA gas may be performed a predeterminednumber of times (e.g., n times). According to this modification, a SiCNfilm is formed on the wafer 200. Processing procedures and processingconditions at the respective steps in this modification may be the sameas those of the respective modifications as described above. Accordingto this modification, the same effects as those of the film formingsequence illustrated in FIG. 4 and those of Modification 3 may beachieved.

(Modification 14)

As illustrated in FIG. 8, a cycle that non-simultaneously performs astep of supplying a HCDS gas, a step of supplying a C₃H₆ gas, a step ofsupplying a NH₃ gas, and a step of supplying an O₂ gas may be performeda predetermined number of times (e.g., n times). According to thismodification, a SiOCN film is formed on the wafer 200. Processingprocedures and processing conditions at the respective steps of thismodification may be the same as those of the respective modifications asdescribed above. According to this modification, the same effects asthose of the film forming sequence illustrated in FIG. 4 and those ofModification 4 may be achieved. Similar to Modification 12, ahydrocarbon-based gas which does not act as a N source is used as thecarbon-containing gas. As such, a composition ratio of the SiOCN filmcan be better controlled. Moreover, the carbon-containing gas isconfined in the process chamber 201. Accordingly, C concentration in theSiOCN layer can be increased significantly.

In this modification, a cycle that non-simultaneously performs the stepof supplying the HCDS gas, the step of supplying the C₃H₆ gas, the stepof supplying the NH₃ gas, and the step of supplying the O₂ gas, in theabove order, may be performed a predetermined number of times (e.g., ntimes). Alternatively, a cycle that non-simultaneously performs the stepof supplying the HCDS gas, the step of supplying the C₃H₆ gas, the stepof supplying the O₂ gas, and the step of supplying the NH₃ gas, in theabove order, may be performed a predetermined number of times (e.g., ntimes). As such, the order of the step of supplying the NH₃ gas and thestep of supplying the O₂ gas may be interchanged. According to any ofthe above orders, the same effects as described above may be achieved.

(Modification 15)

A cycle that non-simultaneously performs a step of supplying a HCDS gas,a step of supplying a TEA gas, and a step of supplying an O₂ gas may beperformed a predetermined number of times (e.g., n times). According tothis modification, a SiOCN film or a SiOC film is formed on the wafer200. Processing procedures and processing conditions at the respectivesteps in this modification may be the same as those of the respectivemodifications as described above. According to this modification, thesame effects as those of the film forming sequence illustrated in FIG. 4and those of Modification 5 may be achieved.

(Modification 16)

A cycle that non-simultaneously performs a step of supplying a HCDS gas,a step of supplying a BCl₃ gas, and a step of supplying a NH₃ gas may beperformed a predetermined number of times (e.g., n times). According tothis modification, a SiBN film is formed on the wafer 200. Processingprocedures and processing conditions at the respective steps in thismodification may be the same as those in the respective modifications asdescribed above. According to this modification, the same effects asthose of the film forming sequence illustrated in FIG. 4 and those ofModification 7 may be achieved.

(Modification 17)

A cycle that non-simultaneously performs a step of supplying a HCDS gas,a step of supplying a C₃H₆ gas, a step of supplying a BCl₃ gas, and astep of supplying a NH₃ gas may be performed a predetermined number oftimes (e.g., n times). According to this modification, a SiBCN film isformed on the wafer 200. Processing procedures and processing conditionsat the respective steps in this modification may be the same as those inthe respective modifications as described above. According to thismodification, the same effects as those of the film forming sequenceillustrated in FIG. 4 and those of Modifications 7 and 12 may beachieved.

In this modification, a cycle that non-simultaneously performs the stepof supplying the HCDS gas, the step of supplying the C₃H₆ gas, the stepof supplying the BCl₃ gas, and the step of supplying the NH₃ gas, in theabove order, may be performed a predetermined number of times (e.g., ntimes). Alternatively, a cycle that non-simultaneously performs the stepof supplying the HCDS gas, the step of supplying the BCl₃ gas, the stepof supplying the C₃H₆ gas, and the step of supplying the NH₃ gas, in theabove order, may be performed a predetermined number of times (e.g., ntimes). As such, the order of the step of supplying the BCl₃ gas and thestep of supplying the C₃H₆ gas may be interchanged. According to any ofthe above orders, the same effects as described above may be achieved.

(Modification 18)

A cycle that non-simultaneously performs a step of supplying a HCDS gas,a step of supplying a BCl₃ gas and a step of supplying a TEA gas may beperformed a predetermined number of times (e.g., n times). According tothis modification, a SiBCN film is formed on the wafer 200. Processingprocedures and processing conditions at the respective steps in thismodification may be the same as those in the respective modifications asdescribed above. According to this modification, the same effects asthose of the film forming sequence illustrated in FIG. 4 and those ofModification 8 may be achieved.

(Modification 19)

A cycle that non-simultaneously performs a step of supplying a HCDS gasand a step of supplying a TMB gas may be performed a predeterminednumber of times (e.g., n times). According to this modification, a SiBCNfilm including a borazine ring skeleton is formed on the wafer 200.Processing procedures and processing conditions at the respective stepsin this modification may be the same as those in the respectivemodifications as described above. According to this modification, thesame effects as those of the film forming sequence illustrated in FIG. 4and those of Modification 9 may be achieved.

(Modification 20)

In the film forming sequence illustrated in FIG. 4 and the respectivemodifications described above, a C₃H₆ gas may be supplied simultaneouslywith a precursor gas such as a BTCSM gas, a HCDS gas, or the like, orsimultaneously with a reaction gas such as a NH₃ gas, an O₂ gas, a TEAgas, a BCl₃ gas, a TMB gas, or the like. Specifically, the step ofsupplying the C₃H₆ gas may be performed simultaneously with at least oneof the steps of supplying the precursor gases or simultaneously with atleast one of the steps of supplying the reaction gases other than theC₃H₆ gas. FIG. 9 illustrates the case where, in Modification 3, the stepof supplying the C₃H₆ gas is performed simultaneously with the step ofsupplying the TEA gas.

The step of supplying the C₃H₆ gas is performed by the same processingprocedures and processing conditions, for example, as those of the stepof supplying the C₃H₆ gas performed in Modification 12. As thecarbon-containing gas, in addition to the C₃H₆ gas, it may be possibleto use the hydrocarbon-based gases as described above.

According to this modification, the same effects as those of the filmforming sequence illustrated in FIG. 4 and those of the respectivemodifications as described above may be achieved. Furthermore, accordingto this modification, a C component contained in the C₃H₆ gas can beadded to the finally formed film. Thus, a composition ratio of thefinally-formed film can be better controlled, and thus, the Cconcentration in the finally-formed film can be increased. However, theC₃H₆ gas may be supplied simultaneously with the NH₃ gas, the O₂ gas,the BCl₃ gas, or the TMB gas, instead of supplying the C₃H₆ gassimultaneously with the BTCSM gas or the HCDS gas. As a result, it ispossible to avoid a gas phase reaction of the C₃H₆ gas in the processchamber 201 and to suppress generation of particles in the processchamber 201. Furthermore, the C₃H₆ gas may be supplied simultaneouslywith the TMB gas or the TEA gas instead of supplying the C₃H₆ gassimultaneously with the BCl₂ gas or the NH₃ gas. As a result, acomposition ratio of the finally-formed film can be better controlled.

<Other Embodiments of the Present Disclosure>

While one embodiment of the present disclosure has been described above,the present disclosure is not limited to the above embodiment, but maybe differently modified without departing from the spirit of the presentdisclosure.

For example, the above embodiment describes the example where the APCvalve 244 is used as an exhaust flow path opening/closing unit. However,the present disclosure is not limited thereto. As an example, instead ofthe APC valve 244 or in addition to the APC valve 244, anopening/closing valve may be installed in the exhaust pipe 231. Thisopening/closing valve may be used as the exhaust flow pathopening/closing unit.

As another example, when the exhaust system is sealed in the aboveembodiment, the APC valve 244 may not be fully closed but may beslightly opened. For example, when a reaction gas is confined in theprocess chamber 201, a flow of the reaction gas moving from an interiorof the process chamber 201 toward the exhaust pipe 231 may be slightlyformed by slightly opening the APC valve 244. Thus, a reaction byproductgenerated in the process chamber 201 or gaseous substance including Cldesorbed from the first layer can be removed from the interior of theprocess chamber 201. As a result, the quality of the film formingprocess can be improved.

As a still another example, as illustrated in FIG. 15, a bypass exhaustpipe (i.e., slow exhaust pipe) 231 a serving as a sub exhaust pipe whichbypasses the APC valve 244 may be installed in the exhaust pipe 231. Aninner diameter of the bypass exhaust pipe 231 a may be set to be smallerthan an inner diameter of the exhaust pipe 231. A valve 244 a and anorifice 244 b as a throttle portion which serves as a conductanceadjusting unit is installed in the bypass exhaust pipe 231 a. With thisconfiguration, the conductance in the bypass exhaust pipe 231 a can bedecreased sufficiently to be smaller than the conductance within theexhaust pipe 231. By opening the valve 244 a and the bypass exhaust pipe231 a when the exhaust system is sealed, the same effects as thoseobtained when slightly opening the APC valve 244 can be achieved, evenif the APC valve 244 is fully closed. A control of the opening degree ofthe APC valve 244 when the exhaust flow path of the exhaust system issealed can also be simplified. The above exhaust system may include abypass exhaust system (or a slow exhaust system) configured with thebypass exhaust pipe 231 a, the valve 244 a, and the orifice 244 b.Moreover, the above exhaust flow path may include a bypass exhaust flowpath (or a slow exhaust flow path) configured with the bypass exhaustpipe 231 a and the orifice 244 b. In addition, a needle valve or thelike provided with an opening degree adjusting mechanism may be used inplace of the orifice 244 b whose opening degree is fixed.

In the aforementioned embodiment, when a precursor gas or a reaction gasis removed from the interior of the process chamber 201, an N₂ gas maybe supplied into the process chamber 201 by opening the valves 243 d and243 e. In this operation, the N₂ gas acts as a purge gas, which canenhance an effect that the gas or reaction byproduct remaining in theprocess chamber 201 is removed from the interior of the process chamber201.

When the precursor gas or the reaction gas is removed from the interiorof the process chamber 201, the gas remaining in the process chamber 201may not be completely removed and the interior of the process chamber201 may not be completely purged. If an amount of gas remaining in theprocess chamber 201 is small, no adverse effect is caused at the stepperformed subsequently. In the case where the N₂ gas is supplied intothe process chamber 201, an amount of the N₂ gas need not be large. Forexample, if the amount of the supplied N₂ gas is substantially equal toa volume of the reaction tube 203 (or the process chamber 201), it ispossible to perform purging in such a manner that no adverse effect iscaused at the step performed subsequently. Inasmuch as the interior ofthe process chamber 201 is not completely purged as described above, itis possible to shorten a purging time and to improve throughput. It isalso possible to reduce consumption of the N₂ gas to a minimum necessarylevel.

Not only at the step of supplying the reaction gas but also at the stepof supplying the precursor gas, the precursor gas may be supplied to thewafer 200 disposed in the process chamber 201 while the exhaust systemis maintained to be sealed and may be confined in the process chamber201. In this operation, the exhaust flow path of the exhaust system maybe sealed. Furthermore, in this operation, an internal pressure of theprocess chamber 201 may be continuously increased by continuouslysupplying the precursor gas into the process chamber 201. In thisoperation, pyrolysis of the precursor gas supplied into the processchamber 201 may be promoted. Eventually, a forming rate of the firstlayer on the wafer 200, that is, a film forming rate of a finally-formedfilm can be increased. Moreover, in this operation, the precursor gasmay be allowed to preliminarily flow through the process chamber 201while the exhaust system is maintained to be opened. The precursor gasmay then be supplied into and confined in the process chamber 201 whilethe exhaust system is maintained to be closed. In this operation, it ispossible to promote removal of reaction byproduct or particles generatedby the reaction of the reaction gas and the precursor gas, which remainin the process chamber 201, from the process chamber 201. As a result,the quality of the finally-formed film can be improved.

The above embodiment describes the example where a reaction gas issupplied after a precursor gas is supplied. The present disclosure isnot limited thereto. The supply order of the precursor gas and thereaction gas may be reversed. Specifically, the precursor gas may besupplied after the reaction gas is supplied. By changing the supplyorder of the precursor gas and the reaction gas, it is possible tochange the quality or composition ratio of the thin film formedaccording to the changed supply order. In the case where plural kinds ofreaction gases are used, the supply order of the reaction gases may bearbitrarily changed. By changing the supply order of the reaction gases,it is possible to change the quality or composition ratio of the thinfilm formed according to the changed supply order.

If the silicon-based insulating film formed by the methods of theembodiment or the modifications as described above is used as a sidewallspacer, it is possible to provide a technique of forming a device whoseleak current is small and workability is superior. If the abovesilicon-based insulating film is used as an etching stopper, it ispossible to provide a technique of forming a device whose workability issuperior. According to the embodiment or some of the modifications asdescribed above, it is possible to form a silicon-based insulating filmhaving an ideal stoichiometric ratio without having to use plasma. Sincethe silicon-based insulating film can be formed without having to useplasma, it is possible to apply to a process for forming, for example, aSADP film of a DPT, in which plasma damage is a concern.

The above embodiment describes the example where the silicon-based thinfilm (i.e., the SiN film, the SiON film, the SiCN film, the SiOCN film,the SiOC film, the SiBCN film or the SiBN film) containing Si as asemiconductor element is formed as a film containing a predeterminedelement. The present disclosure is not limited to the above example, butmay be appropriately applied, for example, to the case where ametal-based thin film containing a metal element such as titanium (Ti),zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), aluminum(Al), molybdenum (Mo), tungsten (W) or the like is formed.

Specifically, the present disclosure may be suitably applied, forexample, to a case where a metal-based thin film such as a TiN film, aTiON film, a TiCN film, a TiOCN film, a TiOC film, a TiBCN film, a TiBNfilm, a ZrN film, a ZrON film, a ZrCN film, a ZrOCN film, a ZrOC film, aZrBCN film, a ZrBN film, a HfN film, a HfON film, a HfCN film, a HfOCNfilm, a HfOC film, a HfBCN film, a HfBN film, a TaN film, a TaON film, aTaCN film, a TaOCN film, a TaOC film, a TaBCN film, a TaBN film, a NbNfilm, a NbON film, a NbCN film, a NbOCN film, a NbOC film, a NbBCN film,a NbBN film, an AIN film, an AlON film, an AlCN film, an AlOCN film, anAlOC film, an AlBCN film, an AIBN film, a MoN film, a MoON film, a MoCNfilm, a MoOCN film, a MoOC film, a MoBCN film, a MoBN film, a WN film, aWON film, a WCN film, a WOCN film, a WOC film, a WBCN film, a WBN filmor the like is formed. In this case, instead of the precursor gascontaining Si used in the above embodiment, a precursor gas containing ametal element may be used as the precursor gas. Film formation may beperformed by the same sequence as that of the embodiment or themodifications as described above.

In the case of forming a Ti-based thin film, for example, a precursorgas containing Ti and a halogen element may be used as a precursor gascontaining Ti. As the precursor gas containing Ti and a halogen element,it may be possible to use, for example, a precursor gas containing Tiand a chloro group such as a titanium tetrachloride (TiCl₄) gas or thelike, or a precursor gas containing Ti and a fluoro group such as atitanium tetrafluoride (TiF₄) gas or the like. As the reaction gas, itmay be possible to use the same gas as used in the above embodiment.Processing conditions used in this case may be the same, for example, asthe processing conditions of the above embodiment.

In the case of forming a Zr-based thin film, for example, a precursorgas containing Zr and a halogen element may be used as a precursor gascontaining Zr. As the precursor gas containing Zr and a halogen element,it may be possible to use, for example, a precursor gas containing Zrand a chloro group such as a zirconium tetrachloride (ZrCl₄) gas or thelike, or a precursor gas containing Zr and a fluoro group such as azirconium tetrafluoride (ZrF₄) gas or the like. As the reaction gas, itmay be possible to use the same gas as used in the aforementionedembodiment. Processing conditions used in this case may be the same, forexample, as the processing conditions of the above embodiment.

In the case of forming a Hf-based thin film, for example, a precursorgas containing Hf and a halogen element may be used as a precursor gascontaining Hf. As the precursor gas containing Hf and a halogen element,it may be possible to use, for example, a precursor gas containing Hfand a chloro group such as a hafnium tetrachloride (HfCl₄) gas or thelike, or a precursor gas containing Hf and a fluoro group such as ahafnium tetrafluoride (HfF₄) gas or the like. As the reaction gas, itmay be possible to use the same gas as used in the above embodiment.Processing conditions used in this case may be the same, for example, asthe processing conditions of the above embodiment.

In the case of forming a Ta-based thin film, for example, a precursorgas containing Ta and a halogen element may be used as a precursor gascontaining Ta. As the precursor gas containing Ta and a halogen element,it may be possible to use, for example, a precursor gas containing Taand a chloro group such as a tantalum pentachloride (TaCl₅) gas or thelike, or a precursor gas containing Ta and a fluoro group such as atantalum pentafluoride (TaF₅) gas or the like. As the reaction gas, itmay be possible to use the same gas as used in the above embodiment.Processing conditions used in this case may be the same, for example, asthe processing conditions of the above embodiment.

In the case of forming a Nb-based thin film, for example, a precursorgas containing Nb and a halogen element may be used as a precursor gascontaining Nb. As the precursor gas containing Nb and a halogen element,it may be possible to use, for example, a precursor gas containing Nband a chloro group such as a niobium pentachloride (NbCl₅) gas or thelike, or a precursor gas containing Nb and a fluoro group such as aniobium pentafluoride (NbF₅) gas or the like. As the reaction gas, itmay be possible to use the same gas as used in the above embodiment.Processing conditions used in this case may be the same, for example, asthe processing conditions of the above embodiment.

In the case of forming an Al-based thin film, for example, a precursorgas containing Al and a halogen element may be used as a precursor gascontaining Al. As the precursor gas containing Al and a halogen element,it may be possible to use, for example, a precursor gas containing Aland a chloro group such as an aluminum trichloride (AlCl₃) gas or thelike, or a precursor gas containing Al and a fluoro group such as analuminum trifluoride (AlF₃) gas or the like. As the reaction gas, it maybe possible to use the same gas as used in the above embodiment.Processing conditions used in this case may be the same, for example, asthe processing conditions of the above embodiment.

In the case of forming a Mo-based thin film, for example, a precursorgas containing Mo and a halogen element may be used as a precursor gascontaining Mo. As the precursor gas containing Mo and a halogen element,it may be possible to use, for example, a precursor gas containing Moand a chloro group such as a molybdenum pentachloride (MoCl₅) gas or thelike, or a precursor gas containing Mo and a fluoro group such as amolybdenum pentafluoride (MoF₅) gas or the like. As the reaction gas, itmay be possible to use the same gas as used in the above embodiment.Processing conditions used in this case may be the same, for example, asthe processing conditions of the above embodiment.

In the case of forming a W-based thin film, for example, a precursor gascontaining W and a halogen element may be used as a precursor gascontaining W. As the precursor gas containing W and a halogen element,it may be possible to use, for example, a precursor gas containing W anda chloro group such as a tungsten hexachloride (WCl₆) gas or the like,or a precursor gas containing W and a fluoro group such as a tungstenhexafluoride (WF₆) gas or the like. As the reaction gas, it may bepossible to use the same gas as used in the above embodiment. Processingconditions used in this case may be the same, for example, as theprocessing conditions of the above embodiment.

That is to say, the present disclosure may be suitably applied to thecase where a thin film containing a predetermined element such as asemiconductor element, a metal element, or the like is formed.

Process recipes (e.g., programs describing processing procedures andprocessing conditions) used in forming these various kinds of films maybe prepared individually (in a plural number) according to the contentsof substrate processing (e.g., a kind, a composition ratio, a quality,and a thickness of a film to be formed). In addition, at the start ofthe substrate processing, an appropriate process recipe may be properlyselected from the process recipes according to the substrate processingcontents. Specifically, the process recipes individually preparedaccording to the substrate processing contents may be stored (orinstalled) in advance in the memory device 121 c of the substrateprocessing apparatus via a telecommunication line or a recording medium(e.g., the external memory device 123) storing the process recipes.Moreover, at the start of the substrate processing, the CPU 121 a of thesubstrate processing apparatus may properly select an appropriateprocess recipe from the process recipes stored in the memory device 121c according to the substrate processing contents. This configurationenables a single substrate processing apparatus to form films ofdifferent kinds, composition ratios, qualities, and thicknesses forgeneral purposes and with enhanced reproducibility. In addition, thisconfiguration can reduce an operator's operation burden (e.g., a burdenborne by an operator when inputting processing procedures and processingconditions), thereby avoiding a manipulation error and quickly startingthe substrate processing.

The process recipes as described above are not limited to newly-preparedones but may be prepared, for example, by modifying existing processrecipes already installed in the substrate processing apparatus. In thecase of modifying the process recipes, the modified process recipes maybe installed in the substrate processing apparatus via atelecommunication line or a recording medium storing the processrecipes. In addition, the existing process recipes already installed inthe substrate processing apparatus may be directly modified by operatingthe input/output device 122 of the substrate processing apparatus.

The above embodiment describes the example in which thin films areformed using a batch type substrate processing apparatus capable ofprocessing a plurality of substrates at one time. The present disclosureis not limited to the above embodiment, but may be appropriatelyapplied, for example, to the case where thin films are formed using asingle-wafer-type substrate processing apparatus capable of processing asingle substrate or several substrates at one time. In addition, theabove embodiment describes the example in which thin films are formedusing a substrate processing apparatus provided with a hot-wall-typeprocessing furnace. The present disclosure is not limited to the aboveembodiment, but may be appropriately applied to the case where thinfilms are formed using a substrate processing apparatus provided with acold-wall-type processing furnace. In these cases, the processingconditions may be the same as those of the above embodiment.

For example, the present disclosure may be appropriately applied to thecase where a film is formed using a substrate processing apparatusprovided with a processing furnace 302 illustrated in FIG. 16A. Theprocessing furnace 302 includes a process vessel 303 which defines aprocess chamber 301, a shower head 303 s configured to supply a gas intothe process chamber 301 in a shower-like manner, a support table 317configured to horizontally support one or more wafers 200, a rotationshaft 355 configured to support the support table 317 from below, and aheater 307 installed in the support table 317. A gas supply port 332 aconfigured to supply the above precursor gas and a gas supply port 332 bconfigured to supply the above reaction gas are connected to inlets(i.e., gas introduction holes) of the shower head 303 s. A precursor gassupply system identical to the precursor gas supply system of the aboveembodiment is connected to the gas supply port 332 a. A reaction gassupply system identical to the reaction gas supply system of the aboveembodiment is connected to the gas supply port 332 b. A gas distributionplate configured to supply a gas into the process chamber 301 in ashower-like manner is installed in outlets (i.e., gas discharge holes)of the shower head 303 s. An exhaust port 331 configured to evacuate aninterior of the process chamber 301 is installed in the process vessel303. An exhaust system identical to the exhaust system of the aboveembodiment is connected to the exhaust port 331.

As another example, the present disclosure may be appropriately appliedto the case where a film is formed using a substrate processingapparatus provided with a processing furnace 402 illustrated in FIG.16B. The processing furnace 402 includes a process vessel 403 whichdefines a process chamber 401, a support table 417 configured tohorizontally support one or more wafers 200, a rotation shaft 455configured to support the support table 417 from below, a lamp heater407 configured to irradiate light toward the wafer 200 disposed withinthe process vessel 403, and a quartz window 403 w which transmits thelight irradiated from the lamp heater 407. A gas supply port 432 aconfigured to supply the above precursor gas and a gas supply port 432 bconfigured to the supply the above reaction gas are connected to theprocess vessel 403. A precursor gas supply system identical to theprecursor gas supply system of the above embodiment is connected to thegas supply port 432 a. A reaction gas supply system identical to thereaction gas supply system of the above embodiment is connected to thegas supply port 432 b. An exhaust port 431 configured to evacuate aninterior of the process chamber 401 is installed in the process vessel403. An exhaust system identical to the exhaust system of theaforementioned embodiment is connected to the exhaust port 431.

In the case of using these substrate processing apparatuses, filmformation can be performed by the same sequences and processingconditions as those of the embodiments and modifications as describedabove.

The embodiments and modifications described above may be appropriatelycombined with one another. In addition, processing conditions for suchcombinations may be the same, for example, as the processing conditionsof the embodiments described above.

EXAMPLES

In Example 1, using the substrate processing apparatus of the aboveembodiment, a SiCN film was formed on a wafer according to the filmforming sequence illustrated in FIG. 4. A BTCSM gas was used as aprecursor gas. A NH₃ gas was used as a reaction gas. At a step ofsupplying the BTCSM gas, a supply flow rate of the BTCSM gas was set tobe 100 sccm and a supply flow rate of an N₂ gas was set to be 100 sccm.An APC valve was controlled such that an internal pressure of a processchamber is kept constant at 3 Torr (400 Pa). At a step of supplying theNH₃ gas, a supply flow rate of the NH₃ gas was set to be 1,000 sccm anda supply flow rate of the N₂ gas was set to be 100 sccm. The APC valvewas fully closed. A supply time of the NH₃ gas was set to be 3 seconds.A film forming temperature was set to be 400 degrees C. Other processingconditions were set to fall within the range of the processingconditions used in the above embodiment. FIG. 10A is a view illustratinga change of the internal pressure of the process chamber in the filmforming sequence of this example. The horizontal axis indicates anelapsed time (sec) within one cycle. The vertical axis indicates theinternal pressure (a.u.) of the process chamber.

In Example 2, using the substrate processing apparatus of the aboveembodiment, a SiCN film was formed on a wafer according to the filmforming sequence illustrated in FIG. 5. A BTCSM gas was used as aprecursor gas. A NH₃ gas was used as a reaction gas. At a step ofsupplying the BTCSM gas, a supply flow rate of the BTCSM gas was set tobe 100 sccm and a supply flow rate of an N₂ gas was set to be 100 sccm.The APC valve was controlled such that an internal pressure of theprocess chamber is kept constant at 3 Torr (400 Pa). At a step ofsupplying the NH₃ gas, a supply flow rate of the NH₃ gas was set at1,000 sccm and a supply flow rate of the N₂ gas was set to be 100 sccm.The APC valve was fully closed. A supply time of the NH₃ gas was set tobe 3 seconds. A supply time of the N₂ gas after stopping the supply ofthe NH₃ gas was set to be 12 seconds. A film forming temperature was tobe at 400 degrees C. Other processing conditions were set to fall withinthe range of the processing conditions used in the above embodiment.FIG. 10B is a view illustrating a change of the internal pressure of theprocess chamber in the film forming sequence of this example. Thehorizontal axis indicates an elapsed time (sec) within one cycle. Thevertical axis indicates the internal pressure (a.u.) of the processchamber.

In Example 3, using the substrate processing apparatus of the aboveembodiment, a SiCN film was formed on a wafer according to the filmforming sequence illustrated in FIG. 4. A BTCSM gas was used as aprecursor gas. A NH₃ gas was used as a reaction gas. At a step ofsupplying the BTCSM gas, a supply flow rate of the BTCSM gas was set tobe 100 sccm and a supply flow rate of an N₂ gas was set to be 100 sccm.The APC valve was controlled such that an internal pressure of theprocess chamber is kept constant at 3 Torr (400 Pa). At a step ofsupplying the NH₃ gas, a supply flow rate of the NH₃ gas was set to be1,000 sccm and a supply flow rate of the N₂ gas was set to be 100 sccm.The APC valve was fully closed. A supply time of the NH₃ gas was set tobe 15 seconds. A film forming temperature was set at 400 degrees C.Other processing conditions were set to fall within the range of theprocessing conditions used in the above embodiment. FIG. 10C is a viewillustrating a change of the internal pressure of the process chamber inthe film forming sequence of this example. The horizontal axis indicatesan elapsed time (sec) within one cycle. The vertical axis indicates theinternal pressure (a.u.) of the process chamber.

In a comparative example, using the substrate processing apparatus ofthe above embodiment, a SiCN film was formed on a wafer according to afilm forming sequence in which a step of supplying a BTCSM gas to thewafer in the process chamber and a step of supplying a NH₃ gas to thewafer in the process chamber are alternately performed a predeterminednumber of times. At the step of supplying the BTCSM gas, a supply flowrate of the BTCSM gas was set to be 100 sccm and a supply flow rate ofan N₂ gas was set to be 1,200 sccm. The APC valve was controlled suchthat an internal pressure of the process chamber is kept constant at 5Torr (667 Pa). At the step of supplying the NH₃ gas, a supply flow rateof the NH₃ gas was set to be 500 sccm and a supply flow rate of the N₂gas was set to be 1,200 sccm. The APC valve was controlled such that aninternal pressure of the process chamber is kept constant at 5 Torr (667Pa). That is to say, the APC valve was controlled such that the internalpressures of the process chamber at the respective steps become equal toeach other. Other processing conditions were set to fall within therange of the processing conditions used in the aforementionedembodiment. FIG. 11 is a view illustrating a change of the internalpressure of the process chamber in the film forming sequence of thecomparative example. The horizontal axis in FIG. 11 indicates an elapsedtime (sec) within one cycle. The vertical axis indicates the internalpressure (a.u.) of the process chamber.

Film forming rates of the SiCN films in the respective examples and thecomparative example were measured. FIG. 12 is a view illustrating thefilm forming rates of the SiCN films in the respective examples and thecomparative example. The vertical axis in FIG. 12 indicates a thicknessof the SiCN film formed per one cycle, that is, a cycle rate (Å/cycle).The horizontal axis indicates the comparative example and the respectiveexamples in order. As such, FIG. 12 illustrates the cycle rates as thefilm forming rates of the SiCN films in the respective examples and thecomparative example.

It can be noted in FIG. 12 that the film forming rates (0.24, 0.22, and0.38 Å/cycle in order) of Examples 1 to 3 are higher than the filmforming rate (0.06 Å/cycle) of the comparative example. Thus, it can beappreciated that the film forming rates of the SiCN films are improvedby supplying the NH₃ gas to the wafer in the process chamber while theexhaust system is sealed, and the NH₃ gas is confined in the processchamber. It can also be appreciated that the film forming rate ofExample 3 is higher than the film forming rates of Examples 1 and 2.Thus, it can be noted that the film forming rates of the SiCN films arefurther improved by continuously supplying the NH₃ gas into the processchamber, that is, by continuously increasing the internal pressure ofthe process chamber, when the NH₃ gas is confined in the processchamber.

<Aspects of the Present Disclosure>

Hereinafter, some aspects of the present disclosure are additionallydescribed as supplementary notes.

(Supplementary Note 1)

According to one aspect of the present disclosure, there are provided amethod of manufacturing a semiconductor device and a method ofprocessing a substrate, including forming a film on the substrate byperforming a cycle a predetermined number of times, the cycle includingnon-simultaneously performing: (a) supplying a precursor gas to thesubstrate in a process chamber; (b) exhausting the precursor gas in theprocess chamber through an exhaust system; (c) confining a reaction gas,which differs in chemical structure from the precursor gas, in theprocess chamber by supplying the reaction gas to the substrate in theprocess chamber while the exhaust system is closed; and (d) exhaustingthe reaction gas in the process chamber through the exhaust system whilethe exhaust system is opened

(Supplementary Note 2)

According to the method of Supplementary Note 1, in the (c), the exhaustsystem (e.g., an exhaust flow path of the exhaust system) may be sealed.

(Supplementary Note 3)

According to the method of Supplementary Note 1 or 2, in the (c), anexhaust flow path of the exhaust system may be fully closed

(Supplementary Note 4)

According to the method of any one of Supplementary Notes 1 to 3, in the(c), an exhaust flow path opening/closing unit (e.g., an exhaust valve)installed in the exhaust system may be fully closed.

(Supplementary Note 5)

According to the method of any one of Supplementary Notes 1 to 4, in the(c), the reaction gas may be continuously supplied into the processchamber.

(Supplementary Note 6)

According to the method of any one of Supplementary Notes 1 to 5, in the(c), an internal pressure of the process chamber may be continuouslyincreased.

(Supplementary Note 7)

According to the method of any one of Supplementary Notes 1 to 6, in the(c), the reaction gas may be allowed to preliminarily flow through theprocess chamber while the exhaust system is opened, and the reaction gasmay then be supplied into and confined in the process chamber while theexhaust system is closed.

(Supplementary Note 8)

According to the method of any one of Supplementary Notes 1 to 7, atarget internal pressure of the process chamber in the (c) may be set tobe higher than a target internal pressure of the process chamber in the(a).

(Supplementary Note 9)

According to the method of any one of Supplementary Notes 1 to 8, anopening degree of an exhaust flow path of the exhaust system in the (c)may be set to be smaller than an opening degree of the exhaust flow pathin the (a).

(Supplementary Note 10)

According to the method of any one of Supplementary Notes 1 to 9, anopening degree of an exhaust flow path opening/closing unit installed inthe exhaust system in the (c) may be set to be smaller than an openingdegree of the exhaust flow path opening/closing unit in the (a).

(Supplementary Note 11)

According to the method of any one of Supplementary Notes 1 to 10, thereaction gas may include at least one selected from a group consistingof a nitrogen-containing gas (e.g., a hydrogen nitride-based gas), acarbon-containing gas (e.g., a hydrocarbon-based gas), a nitrogen- andcarbon-containing gas (e.g., an amine-based gas and an organichydrazine-based gas), a boron-containing gas (e.g., a borane-based gas),and a boron-, nitrogen- and carbon-containing gas (e.g., aborazine-based gas).

(Supplementary Note 12)

According to the method of any one of Supplementary Notes 1 to 11, thereaction gas may include a nitrogen-containing gas (e.g., nitridinggas).

(Supplementary Note 13)

According to the method of any one of Supplementary Notes 1 to 12, thereaction gas may include a hydrogen nitride-based gas.

(Supplementary Note 14)

According to the method of any one of Supplementary Notes 1 to 13, thereaction gas may include at least one selected from a group consistingof an ammonia gas, a hydrazine gas, and a diazene gas.

(Supplementary Note 15)

According to the method of any one of Supplementary Notes 1 to 14, thecycle may be performed a predetermined number of times under anon-plasma condition.

(Supplementary Note 16)

According to another aspect of the present disclosure, there is provideda substrate processing apparatus, including a process chamber configuredto accommodate a substrate; precursor gas supply system configured tosupply a precursor gas into the process chamber; a reaction gas supplysystem configured to supply a reaction gas, which differs in chemicalstructure from the precursor gas, into the process chamber; an exhaustsystem configured to evacuate an interior of the process chamber; and acontrol unit configured to control the precursor gas supply system, thereaction gas supply system, and the exhaust system so as to perform aprocess of forming a film on the substrate by performing a cycle apredetermined number of times, the cycle including non-simultaneouslyperforming: (a) supplying the precursor gas to the substrate in theprocess chamber; (b) exhausting the precursor gas in the process chamberthrough the exhaust system; (c) confining the reaction gas, whichdiffers in chemical structure from the precursor gas, in the processchamber by supplying the reaction gas to the substrate in the processchamber while the exhaust system is closed; and (d) exhausting thereaction gas in the process chamber through the exhaust system while theexhaust system is opened.

(Supplementary Note 17)

According to a still another aspect of the present disclosure, there areprovided a program and a non-transitory computer-readable recordingmedium storing the program, wherein the program causes a computer toperform a process of forming a film on a substrate by performing a cyclea predetermined number of times, the cycle including non-simultaneouslyperforming: (a) supplying a precursor gas to the substrate in a processchamber; (b) exhausting the precursor gas in the process chamber throughan exhaust system; (c) confining a reaction gas, which differs inchemical structure from the precursor gas, in the process chamber bysupplying the reaction gas to the substrate in the process chamber whilethe exhaust system is closed; and (d) exhausting the reaction gas in theprocess chamber through the exhaust system while the exhaust system isopened.

According to the present disclosure, it is possible to improveproductivity of a process of forming a film and quality of such a filmwithout having to use plasma when the film is formed on a substrateusing a precursor gas and a reaction gas.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the novel methods and apparatusesdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe embodiments described herein may be made without departing from thespirit of the disclosures. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of the disclosures.

What is claimed is:
 1. A method of manufacturing a semiconductor device,comprising: forming a film on a substrate by performing a cycle apredetermined number of times, the cycle including non-simultaneouslyperforming: (a) supplying a precursor gas to the substrate in a processchamber; (b) exhausting the precursor gas in the process chamber throughan exhaust system; (c) confining a reaction gas, which differs inchemical structure from the precursor gas, in the process chamber bysupplying the reaction gas to the substrate in the process chamber whilethe exhaust system is sealed; and (d) exhausting the reaction gas in theprocess chamber through the exhaust system while the exhaust system isopened, wherein, in the act of (c), the reaction gas is allowed topreliminarily flow through the process chamber while the exhaust systemis opened, and the reaction gas is then supplied into and confined inthe process chamber while the exhaust system is sealed, and wherein thereaction gas comprises at least one selected from a group consisting ofan ammonia gas, a hydrazine gas, a diazene gas, an amine-based gas, andan organic hydrazine-based gas.
 2. The method of claim 1, wherein, in aperiod in which the exhaust system is sealed in the act of (c), anexhaust flow path opening/closing unit installed in the exhaust systemis fully closed.
 3. The method of claim 1, wherein, in the act of (c),the reaction gas is continuously supplied into the process chamber. 4.The method of claim 1, wherein, in the act of (c), an internal pressureof the process chamber is continuously increased.
 5. The method of claim1, wherein the act of (a) includes setting an internal pressure of theprocess chamber to a first pressure, and the act of (c) includes settingthe internal pressure of the process chamber to a second pressure higherthan the first pressure.
 6. The method of claim 1, wherein an openingdegree of an exhaust flow path of the exhaust system in the act of (c)is set to be smaller than an opening degree of the exhaust flow path inthe act of (a).
 7. The method of claim 1, wherein an opening degree ofan exhaust flow path opening/closing unit installed in the exhaustsystem in the act of (c) is set to be smaller than an opening degree ofthe exhaust flow path opening/closing unit in the act of (a).
 8. Themethod of claim 1, wherein the reaction gas comprises at least oneselected from a group consisting of a nitrogen-containing gas, acarbon-containing gas, a nitrogen- and carbon-containing gas, aboron-containing gas, and a boron-, nitrogen- and carbon-containing gas.9. The method of claim 1, wherein the reaction gas comprises a hydrogennitride-based gas.
 10. The method of claim 1, wherein the reaction gasis an ammonia gas.
 11. The method of claim 1, wherein the reaction gasis an amine-based gas.
 12. The method of claim 1, wherein the cycle isperformed the predetermined number of times under a non-plasmacondition.
 13. The method of claim 1, wherein the act of (a) includessetting an opening degree of the exhaust flow path opening/closing unitto a first degree, and wherein the act of (c) includes setting theopening degree of the exhaust flow path opening/closing unit installedin the exhaust system to a second degree smaller than the first degreeduring a period when the reaction gas preliminarily flows through theprocess chamber.
 14. The method of claim 1, wherein the reaction gas isa hydrazine gas.
 15. The method of claim 1, wherein the reaction gas isa diazene gas.